Organometallic compound, organic light-emitting device including the same, and diagnostic composition including the organometallic compound

ABSTRACT

An organometallic compound represented by Formula 1:wherein, in Formula 1, groups and variables are the same as described in the specification.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation application of U.S. application Ser. No.16/043,323, filed on Jul. 24, 2018, which claims priority to KoreanPatent Application No. 10-2017-0094963, filed on Jul. 26, 2017, in theKorean Intellectual Property Office, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the contents of which are incorporatedherein in their entirety by reference.

BACKGROUND 1. Field

One or more embodiments relate to an organometallic compound, an organiclight-emitting device including the organometallic compound, and adiagnostic composition including the organometallic compound.

2. Description of the Related Art

Organic light-emitting devices (OLEDs) are self-emission devices, whichhave superior characteristics in terms of a viewing angle, a responsetime, luminance, a driving voltage, and a response speed, and whichproduce full-color images.

In an example, an organic light-emitting device includes an anode, acathode, and an organic layer disposed between the anode and thecathode, wherein the organic layer includes an emission layer. A holetransport region may be disposed between the anode and the emissionlayer, and an electron transport region may be disposed between theemission layer and the cathode. Holes provided from the anode may movetoward the emission layer through the hole transport region, andelectrons provided from the cathode may move toward the emission layerthrough the electron transport region. The holes and the electronsrecombine in the emission layer to produce excitons. These excitonstransit from an excited state to a ground state, thereby generatinglight.

Meanwhile, luminescent compounds may be used to monitor, sense, ordetect a variety of biological materials including cells and proteins.An example of such luminescent compounds is a phosphorescent luminescentcompound.

Various types of organic light emitting devices are known. However,there still remains a need in OLEDs having low driving voltage, highefficiency, high brightness, and long lifespan.

SUMMARY

Aspects of the present disclosure provide an organometallic compound, anorganic light-emitting device including the organometallic compound, anda diagnostic composition including the organometallic compound.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to one or more embodiments, an organometallic compoundrepresented by Formula 1 is provided.

In Formula 1,

-   -   M may be beryllium (Be), magnesium (Mg), aluminum (Al), calcium        (Ca), titanium (Ti), manganese (Mn), cobalt (Co), copper (Cu),        zinc (Zn), gallium (Ga), germanium (Ge), zirconium (Zr),        rhutenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag),        rhenium (Re), platinum (Pt), or gold (Au),    -   X₁ may be a chemical bond, O, S, N(R′), P(R′), B(R′), C(R′)(R″),        Si(R′)(R″), or N(R′)(R″), and when X₁ is a chemical bond, Y₁ is        directly bonded with M,    -   a bond between X₁ and M may be a covalent bond,    -   X₂ to X₄ may each independently be N or C,    -   one bond selected from a bond between X₂ and M, a bond between        X₃ and M, and a bond between X₄ and M is a covalent bond, and        the remaining two bonds are coordinate bonds,    -   Y₁ and Y₃ to Y₅ may each independently be C or N,    -   regarding a pair of X₂ and Y₃, a pair of X₂ and Y₄, a pair of Y₄        and Y₅, a pair of X₅₁ and Y₃, and a pair of X₅₁ and Y₅,        components constituting each pair may be connected to each other        via a chemical bond,    -   CY₁ to CY₅ may each independently be selected from a C₅-C₃₀        carbocyclic group and a C₁-C₃₀ heterocyclic group,    -   a cyclometalated ring formed by CY₅, CY₂, CY₃, and M may be a        6-membered ring,    -   X₅₁ may be selected from O, S, N-[(L₇)_(b7)-(R₇)_(c7)],        C(R₇)(R₈), Si(R₇)(R₈), Ge(R₇)(R₈), C(═O), N, C(R₇), Si(R₇), and        Ge(R₇),    -   R₇ and R₈ may be optionally bonded to each other via a first        linking group to form a substituted or unsubstituted C₅-C₃₀        carbocyclic group or a substituted or unsubstituted C₁-C₃₀        heterocyclic group,    -   L₁ to L₄ and L₇ may each independently be selected from a single        bond, a substituted or unsubstituted C₅-C₃₀ carbocyclic group,        and a substituted or unsubstituted C₁-C₃₀ heterocyclic group,    -   b1 to b4 and b7 may each independently be an integer from 1 to        5,    -   R₁ to R₄, R₇, R₈, R′, and R″ may each independently selected        from hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl        group, a cyano group, a nitro group, an amidino group, a        hydrazine group, a hydrazone group, a carboxylic acid group or a        salt thereof, a sulfonic acid group or a salt thereof, a        phosphoric acid group or a salt thereof, a substituted or        unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted        C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀        alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy        group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a        substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a        substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a        substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a        substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or        unsubstituted C₆-C₆₀ aryloxy group, a substituted or        unsubstituted C₆-C₆₀ arylthio group, a substituted or        unsubstituted C₁-C₆₀ heteroaryl group, a substituted or        unsubstituted monovalent non-aromatic condensed polycyclic        group, a substituted or unsubstituted monovalent non-aromatic        condensed heteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅),        —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉),    -   c1 to c4 and c7 may each independently be an integer from 1 to        5,    -   Z₁ to Z₄ may each independently be a cyano group (CN)—containing        group,    -   a1 to a4 and n1, n2, n3, and n4 may each independently be an        integer from 0 to 20,    -   two of a plurality of neighboring groups R₁ may optionally be        linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic        group or a substituted or unsubstituted C₁-C₃₀ heterocyclic        group,    -   two of a plurality of neighboring groups R₂ may optionally be        linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic        group or a substituted or unsubstituted C₁-C₃₀ heterocyclic        group,    -   two of a plurality of neighboring groups R₃ may optionally be        linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic        group or a substituted or unsubstituted C₁-C₃₀ heterocyclic        group,    -   two of a plurality of neighboring groups R₄ may optionally be        linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic        group or a substituted or unsubstituted C₁-C₃₀ heterocyclic        group,    -   two or more neighboring substituents selected from groups R₁ to        R₄, R₇, and R₈ may optionally be linked to form a substituted or        unsubstituted C₅-C₃₀ carbocyclic group or a substituted or        unsubstituted C₁-C₃₀ heterocyclic group,    -   i) when X₅₁ is O, S, C(═O), or N, the sum of n1, n2, n3, and n4        may be 1 or more, ii) when X₅₁ is N[(L₇)_(b7)-(R₇)_(c7)], C(R₇),        Si(R₇), or Ge(R₇), R₇ may be a cyano group-containing group or        the sum of n1, n2, n3, and n4 may be 1 or more, iii) when X₅₁ is        C(R₇)(R₈), Si(R₇)(R₈), or Ge(R₇)(R₈), at least one selected from        R₇ and R₈ may be a cyano group-containing group or the sum of        n1, n2, n3, and n4 may be 1 or more,    -   at least one of substituents of the substituted C₅-C₃₀        carbocyclic group, substituted C₁-C₃₀ heterocyclic group,        substituted C₁-C₆₀ alkyl group, substituted C₂-C₆₀ alkenyl        group, substituted C₂-C₆₀ alkynyl group, substituted C₁-C₆₀        alkoxy group, substituted C₃-C₁₀ cycloalkyl group, substituted        C₁-C₁₀ heterocycloalkyl group, substituted C₃-C₁₀ cycloalkenyl        group, substituted C₁-C₁₀ heterocycloalkenyl group, substituted        C₆-C₆₀ aryl group, substituted C₆-C₆₀ aryloxy group, substituted        C₆-C₆₀ arylthio group, substituted C₁-C₆₀ heteroaryl group,        substituted monovalent non-aromatic condensed polycyclic group,        and substituted monovalent non-aromatic condensed        heteropolycyclic group may be selected from:    -   deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,        —CFH₂, a hydroxyl group, a cyano group, a nitro group, an        amidino group, a hydrazine group, a hydrazone group, a        carboxylic acid group or a salt thereof, a sulfonic acid group        or a salt thereof, a phosphoric acid group or a salt thereof, a        C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl        group, and a C₁-C₆₀ alkoxy group;    -   a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl        group, and a C₁-C₆₀ alkoxy group, each substituted with at least        one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H,        —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a        nitro group, an amidino group, a hydrazine group, a hydrazone        group, a carboxylic acid group or a salt thereof, a sulfonic        acid group or a salt thereof, a phosphoric acid group or a salt        thereof, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl        group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl        group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀        arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent        non-aromatic condensed polycyclic group, a monovalent        non-aromatic condensed heteropolycyclic group, —N(Q₁₁)(Q₁₂),        —Si(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), and —P(═O)(Q₁₈)(Q₁₉);    -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a        C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a        C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio        group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic        condensed polycyclic group, and a monovalent non-aromatic        condensed heteropolycyclic group;    -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a        C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a        C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio        group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic        condensed polycyclic group, and a monovalent non-aromatic        condensed heteropolycyclic group, each substituted with at least        one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H,        —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a        nitro group, an amidino group, a hydrazine group, a hydrazone        group, a carboxylic acid group or a salt thereof, a sulfonic        acid group or a salt thereof, a phosphoric acid group or a salt        thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀        alkynyl group, a C₁-C₆₀₀ alkoxy group, a C₃-C₁₀ cycloalkyl        group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl        group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a        C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀        heteroaryl group, a monovalent non-aromatic condensed polycyclic        group, a monovalent non-aromatic condensed heteropolycyclic        group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), and        —P(═O)(Q₂₈)(Q₂₉); and    -   N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇) and        —P(═O)(Q₃₈)(Q₃₉),    -   wherein Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉ and Q₃₁ to Q₃₉ may each        independently be selected from hydrogen, deuterium, —F, —Cl,        —Br, —I, a hydroxyl group, a cyano group, a nitro group, an        amidino group, a hydrazine group, a hydrazone group, a        carboxylic acid group or a salt thereof, a sulfonic acid group        or a salt thereof, a phosphoric acid group or a salt thereof, a        C₁-C₆₀ alkyl group, a C₁-C₆₀ alkyl group substituted with at        least one selected from deuterium, a C₁-C₆₀ alkyl group, and a        C₆-C₆₀ aryl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl        group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a        C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a        C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀        aryl group substituted with at least one selected from        deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group, a        C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀        heteroaryl group, a monovalent non-aromatic condensed polycyclic        group, and a monovalent non-aromatic condensed heteropolycyclic        group.    -   Another aspect of the present disclosure provides an organic        light-emitting device including:    -   a first electrode,    -   a second electrode, and    -   an organic layer disposed between the first electrode and the        second electrode,    -   wherein the organic layer includes an emission layer and at        least one organometallic compound.

The organometallic compound of the organic layer may act as a dopant.

Another aspect of the present disclosure provides a diagnosticcomposition including at least one organometallic compound representedby Formula 1.

BRIEF DESCRIPTION OF THE DRAWING

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the FIGURE which is a schematic view of an organiclight-emitting device according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout. In this regard, the presentembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein.

Accordingly, the embodiments are merely described below, by referring tothe FIGURES, to explain aspects. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items. Expressions such as “at least one of,” when preceding alist of elements, modify the entire list of elements and do not modifythe individual elements of the list.

It will be understood that when an element is referred to as being “on”another element, it can be directly in contact with the other element orintervening elements may be present therebetween. In contrast, when anelement is referred to as being “directly on” another element, there areno intervening elements present.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers, and/or sections, these elements, components, regions, layers,and/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer, orsection from another element, component, region, layer, or section.Thus, a first element, component, region, layer, or section discussedbelow could be termed a second element, component, region, layer, orsection without departing from the teachings of the present embodiments.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise.

The term “or” means “and/or.” It will be further understood that theterms “comprises” and/or “comprising,” or “includes” and/or “including”when used in this specification, specify the presence of statedfeatures, regions, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, regions, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this general inventive conceptbelongs. It will be further understood that terms, such as those definedin commonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand the present disclosure, and will not be interpreted in an idealizedor overly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to crosssection illustrations that are schematic illustrations of idealizedembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, embodiments described herein should not beconstrued as limited to the particular shapes of regions as illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, a region illustrated or described asflat may, typically, have rough and/or nonlinear features. Moreover,sharp angles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present claims.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

In an embodiment, an organometallic compound is provided. Theorganometallic compound according to an embodiment is represented byFormula 1 below:

M in Formula 1 may be beryllium (Be), magnesium (Mg), aluminum (Al),calcium (Ca), titanium (Ti), manganese (Mn), cobalt (Co), copper (Cu),zinc (Zn), gallium (Ga), germanium (Ge), zirconium (Zr), rhutenium (Ru),rhodium (Rh), palladium (Pd), silver (Ag), rhenium (Re), platinum (Pt),or gold (Au).

For example, M in Formula 1 may be platinum, but embodiments of thepresent disclosure are not limited thereto.

The organometallic compound represented by Formula 1 may not consist ofan ion pair of a cation and an anion, that is, may be neutral.

X₁ in Formula 1 may be a chemical bond (for example, a single bond or acovalent bond), O, S, N(R′), P(R′), B(R′), C(R′)(R″), Si(R′)(R″), orN(R′)(R″), and a bond between X₁ and M may be a covalent bond. When X₁is a chemical bond, Y₁ may be directly bonded with M.

For example, X₁ in Formula 1 may be chemical bond or O, but embodimentsof the present disclosure are not limited thereto.

In Formula 1, X₂ to X₄ may each independently be N or C, and one bondselected from a bond between X₂ and M, a bond between X₃ and M, and abond between X₄ and M may be a covalent bond, and the remaining twobonds may each be a coordinate bond.

For example, in Formula 1,

-   -   i) X₂ and X₄ may each be N, X₃ may be C, a bond between X₂ and M        and a bond between X₄ and M may each be a coordinate bond, and a        bond between X₃ and M may be a covalent bond,    -   ii) X₃ and X₄ may each be N, X₂ may be N, a bond between X₃ and        M and a bond between X₄ and M may each be a coordinate bond, and        a bond between X₂ and M may be a covalent bond,    -   iii) X₂ and X₃ may each be N, X₄ may be N, a bond between X₂ and        M may be a covalent bond, and a bond between X₃ and M and a bond        between X₄ and M may each be coordinate bond, or    -   iv) X₂ and X₃ may each be N, X₄ may be C, a bond between X₂ and        M and a bond between X₃ and M may each be a coordinate bond, and        a bond between X₄ and M may be a covalent bond, but embodiments        of the present disclosure are not limited thereto.

Y₁ and Y₃ to Y₅ in Formula 1 may each independently be C or N.

A pair of X₂ and Y₃, a pair of X₂ and Y₄, a pair of Y₄ and Y₅, a pair ofX₅₁ and Y₃, and a pair of X₅₁ and Y₅ in Formula 1 may each be bonded viaa chemical bond (for example, a single bond, a double bond, a bondconstituting a carbene ligand, or the like) to form a part of CY₁ toCY₅.

CY₁ to CY₅ in Formula 1 may each independently be selected from a C₅-C₃₀carbocyclic group and a C₁-C₃₀ heterocyclic group.

In one or more embodiments, in Formula 1,

-   -   CY₁, CY₂, and CY₄ may each independently be a 6-membered ring        group,    -   CY₃ may be selected from a 6-membered ring group, a fluorene        group, a carbazole group, a dibenzofuran group, a        dibenzothiophene group, a dibenzosilole group, an azafluorene        group, an azacarbazole group, an azadibenzofuran group, an        azadibenzothiophene group, and an azadibenzosilole group,    -   CY₅ may be a 5-membered ring.

In one or more embodiments, CY₁ to CY₄ in Formula 1 may eachindependently be selected from a benzene group, a naphthalene group, ananthracene group, a phenanthrene group, a triphenylene group, a pyrenegroup, a chrysene group, a cyclopentadiene group, a1,2,3,4-tetrahydronaphthalene group, a furan group, a thiophene group, asilole group, an indene group, a fluorene group, an indole group, acarbazole group, a benzofuran group, a dibenzofuran group, abenzothiophene group, a dibenzothiophene group, a benzosilole group, adibenzosilole group, an azafluorene group, an azacarbazole group, anazadibenzofuran group, an azadibenzothiophene group, an azadibenzosilolegroup, a pyridine group, a pyrimidine group, a pyrazine group, apyridazine group, a triazine group, a quinoline group, an isoquinolinegroup, a quinoxaline group, a quinazoline group, phenanthroline group, apyrrole group, a pyrazole group, an imidazole group, a triazole group,an oxazole group, an iso-oxazole group, a thiazole group, an isothiazolegroup, an oxadiazole group, a thiadiazole group, a benzopyrazole group,a benzimidazole group, a benzoxazole group, a benzothiazole group, abenzooxadiazole group, a benzothiadiazole group, a5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinolinegroup, but embodiments of the present disclosure are not limitedthereto.

In one or more embodiments, CY₁ to CY₄ in Formula 1 may eachindependently be selected from a) 6-membered ring, b) a condensed ringin which two or more 6-membered rings are condensed with each other, orc) a condensed ring in which one or more 6-membered ring is condensedwith one or more 5-membered ring,

-   -   the 6-membered ring may be selected from a cyclohexane group, a        cyclohexene group, an adamantane group, a norbornane group, a        norbornene group, a benzene group, a pyridine group, a        pyrimidine group, a pyrazine group, a pyridazine group, and a        triazine group, and    -   the 5-membered ring may be selected from a cyclopentane group, a        cyclopentene group, a cyclopentadiene group, a furan group, a        thiophene group, a silole group, a pyrrole group, a pyrazole        group, an imidazole group, a triazole group, an oxazole group,        an isoxazole group, a thiazole group, an isothiazole group, an        oxadiazole group and thiadiazole group.

A cyclometalated ring formed by CY₅, CY₂, CY₃, and M in Formula 1 is a6-membered ring.

X₅₁ in Formula 1 may be selected from O, S, N-[(L₇)_(b7)-(R₇)_(c7)],C(R₇)(R₈), Si(R₇)(R₈), Ge(R₇)(R₈), C(═O), N, C(R₇), Si(R₇), and Ge(R₇),and R₇ and R₈ may optionally be linked via a first linking group to forma substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substitutedor unsubstituted C₁-C₃₀ heterocyclic group (for example, a 5-membered to7-membered cyclic group having the carbon number of 5 or 6; or a5-membered to 7-membered cyclic group of which the carbon number is 5 or6 and which is substituted with at least one selected from deuterium, acyano group, —F, a C₁-C₁₀ alkyl group, and a C₆-C₁₄ aryl group). L₇, b7,R₇, R₈, and c7 will be described in detail.

The first linking group may be selected from a single bond, *—O—*′,*—S—*′. *—C(R₅)(R₆)—*′, *—C(R₅)=*′, *═C(R₆)—*′, *—C(R₅)═C(R₆)—*′,*—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—N(R₅)—*′. *—Si(R₅)(R₆)—*′, and*—P(R₅)(R₆)—*′, R₅ and R₆ may be the same as described in connectionwith R₁, and * and *′ each indicate a binding site to a neighboringatom.

In one or more embodiments, in Formula 1,

-   -   i) Y₃ to Y₅ may each be C, a bond between X₅₁ and Y₃ and a bond        between X₅₁ and Y₅ may each be a single bond, and X₅₁ may be O,        S, N-[(L₇)_(b7)-(R₇)_(c7)], C(R₇)(R₈), Si(R₇)(R₈), Ge(R₇)(R₈),        or C(═O),    -   ii) Y₃ and Y₄ may each be C, Y₅ may be N, a bond between X₅₁ and        Y₃ may be a double bond, a bond between X₅₁ and Y₅ may be a        single bond, and X₅₁ may be N, C(R₇), Si(R₇), or Ge(R₇),    -   iii) Y₃ and Y₅ may each be C, Y₄ may be N, a bond between X₅₁        and Y₃ may be a single bond, a bond between X₅₁ and Y₅ may be a        double bond, and X₅₁ may be N, C(R₇), Si(R₇), or Ge(R₇),    -   iv) Y₃ may be N, Y₄ and Y₅ may each be C, a bond between X₅₁ and        Y₃ may be a single bond, a bond between X₅₁ and Y₅ may be a        double bond, and X₅₁ may be N, C(R₇), Si(R₇), or Ge(R₇), or    -   v) Y₃ to Y₅ may each be C, a bond between X₅₁ and Y₃ may be a        double bond, a bond between X₅₁ and Y₅ may be a single bond, and        X₅₁ may be N, C(R₇), Si(R₇), or Ge(R₇).

L₁ to L₄ and L₇ in Formula 1 may each independently be selected from asingle bond, a substituted or unsubstituted C₅-C₃₀ carbocyclic group,and a substituted or unsubstituted C₁-C₃₀ heterocyclic group.

For example, L₁ to L₄ and L₇ in Formula 1 may each independently beselected from:

-   -   a single bond, a benzene group, a naphthalene group, an        anthracene group, a phenanthrene group, a triphenylene group, a        pyrene group, a chrysene group, a cyclopentadiene group, a furan        group, a thiophene group, a silole group, an indene group, a        fluorene group, an indole group, a carbazole group, a benzofuran        group, a dibenzofuran group, a benzothiophene group, a        dibenzothiophene group, a benzosilole group, a dibenzosilole        group, an azafluorene group, an azacarbazole group, an        azadibenzofuran group, an azadibenzothiophene group, an        azadibenzosilole group, a pyridine group, a pyrimidine group, a        pyrazine group, a pyridazine group, a triazine group, a        quinoline group, an isoquinoline group, a quinoxaline group, a        quinazoline group, phenanthroline group, a pyrrole group, a        pyrazole group, an imidazole group, a triazole group, an oxazole        group, an iso-oxazole group, a thiazole group, an isothiazole        group, an oxadiazole group, a thiadiazole group, a benzopyrazole        group, a benzimidazole group, a benzoxazole group, a        benzothiazole group, a benzooxadiazole group, and a        benzothiadiazole group; and    -   a benzene group, a naphthalene group, an anthracene group, a        phenanthrene group, a triphenylene group, a pyrene group, a        chrysene group, a cyclopentadiene group, a furan group, a        thiophene group, a silole group, an indene group, a fluorene        group, an indole group, a carbazole group, a benzofuran group, a        dibenzofuran group, a benzothiophene group, a dibenzothiophene        group, a benzosilole group, a dibenzosilole group, an        azafluorene group, an azacarbazole group, an azadibenzofuran        group, an azadibenzothiophene group, an azadibenzosilole group,        a pyridine group, a pyrimidine group, a pyrazine group, a        pyridazine group, a triazine group, a quinoline group, an        isoquinoline group, a quinoxaline group, a quinazoline group,        phenanthroline group, a pyrrole group, a pyrazole group, an        imidazole group, a triazole group, an oxazole group, an        iso-oxazole group, a thiazole group, an isothiazole group, an        oxadiazole group, a thiadiazole group, a benzopyrazole group, a        benzimidazole group, a benzoxazole group, a benzothiazole group,        a benzooxadiazole group, and a benzothiadiazole group, each        substituted with at least one selected from deuterium, —F, —Cl,        —Br, —I, a hydroxyl group, a cyano group, a nitro group, an        amino group, an amidino group, a hydrazine group, a hydrazone        group, a carboxylic acid group or a salt thereof, a sulfonic        acid group or a salt thereof, a phosphoric acid group or a salt        thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl        group, a naphthyl group, a pyridinyl group, a pyrimidinyl group,        a triazinyl group, a fluorenyl group, a dimethylfluorenyl group,        a diphenylfluorenyl group, a carbazolyl group, a        phenylcarbazolyl group, a dibenzofuranyl group, a        dibenzothiophenyl group, a dibenzosilolyl group, a        dimethyldibenzosilolyl group, a diphenyldibenzosilolyl group,        —N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and        —P(═O)(Q₃₈)(Q₃₉);    -   Q₃₁ to Q₃₉ may each independently be selected from:    -   —CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂,        —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, and        —CD₂CDH₂;    -   an n-propyl group, an iso-propyl group, an n-butyl group, an        iso-butyl group, a sec-butyl group, a tert-butyl group, an        n-pentyl group, an iso-pentyl group, a sec-pentyl group, a        tert-pentyl group, a phenyl group, and a naphthyl group; and    -   an n-propyl group, an iso-propyl group, an n-butyl group, an        iso-butyl group, a sec-butyl group, a tert-butyl group, an        n-pentyl group, an iso-pentyl group, a sec-pentyl group, a        tert-pentyl group, a phenyl group, and a naphthyl group, each        substituted with at least one selected from deuterium, a C₁-C₁₀        alkyl group, and a phenyl group,    -   but embodiments of the present disclosure are not limited        thereto.

b1 to b4 and b7 in Formula 1 indicate numbers of L₁ to L₄ and L₇,respectively, and may each independently an integer from 1 to 5. When b1is 2 or more, two or more groups L₁ may be identical to or differentfrom each other. b2 to b4 and b7 may each be the same as described inconnection with b1.

In an embodiment, b1 to b4 and b7 in Formula 1 may each be 1 or 2, butembodiments of the present disclosure are not limited thereto.

R₁ to R₄, R₇, R₈, R′ and R″ in Formula 1 may each independently beselected from hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid group or a salt thereof, asulfonic acid group or a salt thereof, a phosphoric acid group or a saltthereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, asubstituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted orunsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstitutedC₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkylgroup, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and—P(═O)(Q₈)(Q₉).

For example, R₁ to R₄, R₇, R₈, R′, and R″ may each independently beselected from:

-   -   hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano        group, a nitro group, an amino group, an amidino group, a        hydrazine group, a hydrazone group, a carboxylic acid group or a        salt thereof, a sulfonic acid group or a salt thereof, a        phosphoric acid group or a salt thereof, —SF₅, C₁-C₂₀ alkyl        group, and a C₁-C₂₀ alkoxy group;    -   a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted        with at least one selected from deuterium, —F, —Cl, —Br, —I,        —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a        cyano group, a nitro group, an amino group, an amidino group, a        hydrazine group, a hydrazone group, a carboxylic acid group or a        salt thereof, a sulfonic acid group or a salt thereof, a        phosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group, a        cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a        cyclooctyl group, an adamantanyl group, a norbornanyl group, a        norbornenyl group, a cyclopentenyl group, a cyclohexenyl group,        a cycloheptenyl group, a phenyl group, a naphthyl group, a        pyridinyl group, and a pyrimidinyl group;    -   a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a        cyclooctyl group, an adamantanyl group, a norbornanyl group, a        norbornenyl group, a cyclopentenyl group, a cyclohexenyl group,        a cycloheptenyl group, a phenyl group, a naphthyl group, a        fluorenyl group, a phenanthrenyl group, an anthracenyl group, a        fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a        chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl        group, an imidazolyl group, a pyrazolyl group, a thiazolyl        group, an isothiazolyl group, an oxazolyl group, an isoxazolyl        group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl        group, a pyridazinyl group, an isoindolyl group, an indolyl        group, an indazolyl group, a purinyl group, a quinolinyl group,        an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl        group, a quinazolinyl group, a cinnolinyl group, a carbazolyl        group, a phenanthrolinyl group, a benzimidazolyl group, a        benzofuranyl group, a benzothiophenyl group, an        isobenzothiazolyl group, a benzoxazolyl group, an        isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an        oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a        dibenzothiophenyl group, a dibenzosilolyl group, a        benzocarbazolyl group, a dibenzocarbazolyl group, an        imidazopyridinyl group, and an imidazopyrimidinyl group;    -   a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a        cyclooctyl group, an adamantanyl group, a norbornanyl group, a        norbornenyl group, a cyclopentenyl group, a cyclohexenyl group,        a cycloheptenyl group, a phenyl group, a naphthyl group, a        fluorenyl group, a phenanthrenyl group, an anthracenyl group, a        fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a        chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl        group, an imidazolyl group, a pyrazolyl group, a thiazolyl        group, an isothiazolyl group, an oxazolyl group, an isoxazolyl        group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl        group, a pyridazinyl group, an isoindolyl group, an indolyl        group, an indazolyl group, a purinyl group, a quinolinyl group,        an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl        group, a quinazolinyl group, a cinnolinyl group, a carbazolyl        group, a phenanthrolinyl group, a benzimidazolyl group, a        benzofuranyl group, a benzothiophenyl group, an        isobenzothiazolyl group, a benzoxazolyl group, an        isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an        oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a        dibenzothiophenyl group, a dibenzosilolyl group, a        benzocarbazolyl group, a dibenzocarbazolyl group, an        imidazopyridinyl group, and an imidazopyrimidinyl group, each        substituted with at least one selected from deuterium, —F, —Cl,        —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl        group, a cyano group, a nitro group, an amino group, an amidino        group, a hydrazine group, a hydrazone group, a carboxylic acid        group or a salt thereof, a sulfonic acid group or a salt        thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀        alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a        cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an        adamantanyl group, a norbornanyl group, a norbornenyl group, a        cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl        group, a phenyl group, a naphthyl group, a fluorenyl group, a        phenanthrenyl group, an anthracenyl group, a fluoranthenyl        group, a triphenylenyl group, a pyrenyl group, a chrysenyl        group, a pyrrolyl group, a thiophenyl group, a furanyl group, an        imidazolyl group, a pyrazolyl group, a thiazolyl group, an        isothiazolyl group, an oxazolyl group, an isoxazolyl group, a        pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a        pyridazinyl group, an isoindolyl group, an indolyl group, an        indazolyl group, a purinyl group, a quinolinyl group, an        isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl        group, a quinazolinyl group, a cinnolinyl group, a carbazolyl        group, a phenanthrolinyl group, a benzimidazolyl group, a        benzofuranyl group, a benzothiophenyl group, an        isobenzothiazolyl group, a benzoxazolyl group, an        isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an        oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a        dibenzothiophenyl group, a dibenzosilolyl group, a        benzocarbazolyl group, a dibenzocarbazolyl group, an        imidazopyridinyl group, an imidazopyrimidinyl group and        —Si(Q₃₃)(Q₃₄)(Q₃₅); and    -   —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇) and —P(═O)(Q₈)(Q₉);    -   wherein Q₁ to Q₉ and Q₃₃ to Q₃₅ are each the same as described        in connection with Q₃₁.

In an embodiment, the R₁ to R₄, R₇, R₈, R′ and R″ are each independentlyselected from:

-   -   hydrogen, deuterium, —F, a cyano group, a nitro group, —SF₅, a        methyl group, an ethyl group, an n-propyl group, an iso-propyl        group, an n-butyl group, an iso-butyl group, a sec-butyl group,        a tert-butyl group, an n-pentyl group, an iso-pentyl group, a        sec-pentyl group, a tert-pentyl group, an n-hexyl group, an        iso-hexyl group, a sec-hexyl group, a tert-hexyl group, an        n-heptyl group, an iso-heptyl group, a sec-heptyl group, a        tert-heptyl group, an n-octyl group, an iso-octyl group, a        sec-octyl group, a tert-octyl group, an n-nonyl group, an        iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an        n-decyl group, an iso-decyl group, a sec-decyl group, a        tert-decyl group, a methoxy group, an ethoxy group, a propoxy        group, a butoxy group, a pentoxy group, a cyclopentyl group, a        cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an        adamantanyl group, a norbornanyl group, a norbornenyl group, a        cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl        group, a phenyl group, a naphthyl group, a pyridinyl group, a        pyrimidinyl group, a fluorenyl group, a carbazolyl group, a        dibenzofuranyl group, a dibenzothiophenyl group, and a        dibenzosilolyl group;    -   a methyl group, an ethyl group, an n-propyl group, an iso-propyl        group, an n-butyl group, an iso-butyl group, a sec-butyl group,        a tert-butyl group, an n-pentyl group, an iso-pentyl group, a        sec-pentyl group, a tert-pentyl group, an n-hexyl group, an        iso-hexyl group, a sec-hexyl group, a tert-hexyl group, an        n-heptyl group, an iso-heptyl group, a sec-heptyl group, a        tert-heptyl group, an n-octyl group, an iso-octyl group, a        sec-octyl group, a tert-octyl group, an n-nonyl group, an        iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an        n-decyl group, an iso-decyl group, a sec-decyl group, a        tert-decyl group, a methoxy group, an ethoxy group, a propoxy        group, a butoxy group, a pentoxy group, a cyclopentyl group, a        cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an        adamantanyl group, a norbornanyl group, a norbornenyl group, a        cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl        group, a phenyl group, a naphthyl group, a pyridinyl group, a        pyrimidinyl group, a fluorenyl group, a carbazolyl group, a        dibenzofuranyl group, a dibenzothiophenyl group, and a        dibenzosilolyl group, each substituted with at least one        selected from deuterium, —F, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,        —CFH₂, a cyano group, a nitro group, a C₁-C₁₀ alkyl group, a        C₁-C₁₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a        cycloheptyl group, a cyclooctyl group, an adamantanyl group, a        norbornanyl group, a norbornenyl group, a cyclopentenyl group, a        cyclohexenyl group, a cycloheptenyl group, a phenyl group, a        naphthyl group, a pyridinyl group, a pyrimidinyl group, a        fluorenyl group, a carbazolyl group, a dibenzofuranyl group, a        dibenzothiophenyl group, a dibenzosilolyl group, and        —Si(Q₃₃)(Q₃₄)(Q₃₅); and    -   N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇) and —P(═O)(Q₈)(Q₉),    -   wherein Q₁ to Q₉ and Q₃₃ to Q₃₅ may be the same as described        above, but embodiments of the present disclosure are not limited        thereto.

In one or more embodiments, R₁ to R₄, R₇, R₈, R′, and R″ may eachindependently be selected from hydrogen, deuterium, —F, a cyano group, anitro group, —SF₅, —CH₃, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂,—C(CD₃)₃, groups represented by Formulae 9-1 to 9-19, groups representedby Formulae 10-1 to 10-140, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇) and—P(═O)(Q₈)(Q₉) (wherein Q₁ to Q₉ may each be the same as describedabove), but embodiments of the present disclosure are not limitedthereto:

In Formulae 9-1 to 9-19 and 10-1 to 10-140,

-   -   * indicates a binding site to a neighboring atom,    -   “Ph” indicates a phenyl group, and    -   “TMS” indicates a trimethylsilyl group.

c1 to c4 and c7 in Formula 1 respectively indicate the numbers of R₁ toR₄ and R₇, and may each independently be an integer from 1 to 5. When c1is two or more, two or more of groups R₁ may be identical to ordifferent from each other. c2 to c4 and c7 are the same as described inconnection with c1.

In one or more embodiments, c1 to c4 and c7 in Formula 1 may be 1 or 2,but embodiments of the present disclosure are not limited thereto.

Z₁ to Z₄ in Formula 1 may each independently be a cyano group(CN)—containing group.

The cyano group-containing group may be

-   -   a cyano group; or    -   a first group substituted with at least one cyano group;    -   the first group may be selected from a substituted or        unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted        C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀        alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy        group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a        substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a        substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a        substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a        substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or        unsubstituted C₆-C₆₀ aryloxy group, a substituted or        unsubstituted C₆-C₆₀ arylthio group, a substituted or        unsubstituted C₁-C₆₀ heteroaryl group, a substituted or        unsubstituted monovalent non-aromatic condensed polycyclic        group, and a substituted or unsubstituted monovalent        non-aromatic condensed heteropolycyclic group.

In an embodiment, the first group may be the same as described inconnection with R₁. For example, the first group may be selected from—SF₅, —CH₃, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, —C(CD₃)₃, groupsrepresented by Formulae 9-1 to 9-19, groups represented by Formulae 10-1to 10-140, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉),but embodiments of the present disclosure are not limited thereto.

When the cyano group-containing group is “the first group substitutedwith at least one a cyano group” and the first group is *—CH₃, it wouldbe understood through the present specification that the cyanogroup-containing group includes *—C(CN)₃, *—CH(CN)₂, and *—CH₂(CN).

In an embodiment, the cyano group-containing group may be a cyano group.

In Formula 1, a1 to a4 indicate the numbers of *-[(L₁)_(b1)-(R₁)_(c1)],*-[(L₂)_(b2)-(R₂)_(c2)], *-[(L₃)_(b3)-(R₃)_(c3)], and*-[(L₄)_(b4)-(R₄)_(c4)], respectively, and n1, n2, n3, and n4 indicatethe numbers of Z₁ to Z₄, respectively, and may each independently be aninteger from 0 to 20. When a1 is two or more, two or more groups*-[(L₁)_(b1)-(R₁)_(c1)] may be identical to or different from eachother, when a2 is two or more, two or more groups*-[(L₂)_(b2)-(R₂)_(c2)] may be identical to or different from eachother, when a3 is two or more, two or more groups*-[(L₃)_(b3)-(R₃)_(c3)] may be identical to or different from eachother, when a4 is two or more, two or more groups*-[(L₄)_(b4)-(R₄)_(c4)] may be identical to or different from eachother, when n1 is two or more, two or more groups Z₁ may be identical toor different from each other, when n2 is two or more, two or more groupsZ₂ may be identical to or different from each other, when n3 is two ormore, two or more groups Z₃ may be identical to or different from eachother, and when n4 is two or more, two or more groups Z₄ may beidentical to or different from each other.

In Formula 1, i) two of a plurality of neighboring groups R₁ mayoptionally be linked to form a substituted or unsubstituted C₅-C₃₀carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclicgroup, ii) two of a plurality of neighboring groups R₂ may optionally belinked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic groupor a substituted or unsubstituted C₁-C₃₀ heterocyclic group, iii) two ofa plurality of neighboring groups R₃ may optionally be linked to form asubstituted or unsubstituted C₅-C₃₀ carbocyclic group or a substitutedor unsubstituted C₁-C₃₀ heterocyclic group, iv) two of a plurality ofneighboring groups R₄ may optionally be linked to form a substituted orunsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstitutedC₁-C₃₀ heterocyclic group, v) two or more selected from groups R₁ to R₄,and R₇ and R₈ may optionally be linked to form a substituted orunsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstitutedC₁-C₃₀ heterocyclic group.

For example, in Formula 1, i) a substituted or unsubstituted C₅-C₃₀carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclicgroup, formed by bonding two of a plurality of neighboring groups R₁,ii) a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃₀ heterocyclic group, formed bybonding two of a plurality of neighboring groups R₂, iii) a substitutedor unsubstituted C₅-C₃₀ carbocyclic group or a substituted orunsubstituted C₁-C₃₀ heterocyclic group, formed by bonding two of aplurality of neighboring groups R₃, iv) a substituted or unsubstitutedC₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀heterocyclic group, formed by bonding two of a plurality of neighboringgroups R₄, and v) a substituted or unsubstituted C₅-C₃₀ carbocyclicgroup or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,formed by bonding two or more selected from R₁ to R₄, R₇, and R₈, mayeach independently be selected from:

-   -   a pentadiene group, a cyclohexane group, a cycloheptane group,        an adamantane group, a bicycle-heptane group, a bicycle-octane        group, a benzene group, a pyridine group, a pyrimidine group, a        pyrazine group, a pyridazine group, a naphthalene group, an        anthracene group, a tetracene group, a phenanthrene group, a        dihydronaphthalene group, a phenalene group, a benzothiophene        group, a benzofuran group, an indene group, an indole group, a        benzosilole group, an azabenzothiophene group, an azabenzofuran        group, an azaindene group, an azaindole group, and an        azabenzosilole group; and    -   a pentadiene group, a cyclohexane group, a cycloheptane group,        an adamantane group, a bicycle-heptane group, a bicycle-octane        group, a benzene group, a pyridine group, a pyrimidine group, a        pyrazine group, a pyridazine group, a naphthalene group, an        anthracene group, a tetracene group, a phenanthrene group, a        dihydronaphthalene group, a phenalene group, a benzothiophene        group, a benzofuran group, an indene group, an indole group, a        benzosilole group, an azabenzothiophene group, an azabenzofuran        group, an azaindene group, an azaindole group, and an        azabenzosilole group, each substituted with at least one        selected from at least one R_(10a);    -   but embodiments of the present disclosure are not limited        thereto.

R_(10a) may be the same as described in connection with R₁.

“An azabenzothiophene, an azabenzofuran, an azaindene, an azaindole, anazabenzosilole, an azadibenzothiophene, an azadibenzofuran, anazafluorene, an azacarbazole, and an azadibenzosilole” each have thesame ring system as “a benzothiophene, a benzofuran, an indene, anindole, a benzosilole, a dibenzothiophene, a dibenzofuran, a fluorene, acarbazole, and a dibenzosilole,” respectively, and each further containa hetero ring in which at least one of ring-forming carbon atoms issubstituted with nitrogen.

In Formula 1,

-   -   i) when X₅₁ is O, S, C(═O), or N, the sum of n1, n2, n3, and n4        may be 1 or more (for example, 1, 2, 3, 4, or 5),    -   ii) when X₅₁ is N[(L₇)_(b7)-(R₇)_(c7)], C(R₇), Si(R₇), or        Ge(R₇), R₇ may be a cyano group-containing group or the sum of        n1, n2, n3, and n4 may be 1 or more (for example, 1, 2, 3, 4, or        5), and    -   iii) when X₅₁ is C(R₇)(R₈), Si(R₇)(R₈), or Ge(R₇)(R₈), at least        one selected from R₇ and R₈ may be a cyano group-containing        group or the sum of n1, n2, n3, and n4 may be 1 or more (for        example, 1, 2, 3, 4, or 5).

That is, the organometallic compound represented by Formula 1essentially includes at least one cyano group-containing group asdefined herein.

In an embodiment, the sum of n1, n2, n3, and n4 in Formula 1 may be 1,2, 3, or 4, for example, 1 or 2. That is, the number of cyanogroup-containing groups included in Formula 1 may be 1, 2, 3, or 4, forexample, 1 or 2, but embodiments of the present disclosure are notlimited thereto.

In one or more embodiments, in Formula 1,

-   -   i) n1=n2=n3=0, and n4=1,    -   ii) n1=n2=n4=0, and n3=1,    -   iii) n1=n3=n4=0, and n2=1,    -   iv) n2=n3=n4=0, and n1=1,    -   v) n1=n2=0, and n3=n4=1,    -   vi) n2=n3=0, and n1=n4=1,    -   vii) n2=n4=0, and n1=n3=1, or    -   viii) n1=n3=0, and n2=n4=1, but embodiments of the present        disclosure are not limited thereto.

In one or more embodiments, in Formula 1,

-   -   i) X₁ is a chemical bond, and a moiety represented by

may be a group represented by Formula CY1-B, or

-   -   ii) X₁ may be O, S, N(R′), P(R′), B(R′), C(R′)(R″), Si(R′)(R″),        or N(R′)(R″), and a moiety represented by

may be a group represented by Formula CY1-A:

In Formulae CY1-A and CY1-B, Y₁, CY₁, L₁, b1, R₁, c1, a1, Z₁, and n1 arethe same as described above, Y₂ and Y₆ may each independently be N or C;and a bond between Y₁ and Y₂, a bond between Y₁ and Y₆ and a bondbetween Y₆ and Y₂ may each be a chemical bond (for example, a singlebond, a double bond, or a bond constituting a carbene ligand, or thelike).

In one or more embodiments, in Formula 1, a moiety represented by

may be a group represented by Formulae CY1-1 to CY1-40:

In Formulae CY1-1 to CY1-40,

-   -   Y₁, R₁, Z₁, and n1 are the same as described above, n1 is 0, 1,        or 2,    -   X₁₉ is C(R_(19a))(R_(19b)), N[(L₁₉)_(b19)-(R₁₉)_(c19)], O, S, or        Si(R_(19a))(R_(19b)),    -   L₁₉ may be the same as explained in connection with L₁,    -   b19 and c19 are the same as described in connection with b1 and        c1,    -   R₁₁ to R₁₉, R_(19a), and R_(19b) may be the same as described in        connection with R₁,    -   a12 may be an integer from 0 to 2,    -   a13 may be an integer from 0 to 3,    -   a14 may be an integer from 0 to 4,    -   a15 may be an integer from 0 to 5,    -   a16 may be an integer from 0 to 6,    -   a17 may be an integer from 0 to 7,    -   *′ indicates a binding site to M in Formula 1, and    -   * indicates a binding site to CY₅ in Formula 1.

In one or more embodiments, in Formula 1, a moiety represented by

may be a group represented by Formulae CY2-1 to CY2-20:

In Formulae CY2-1 to CY2-20,

-   -   R₂, Z₂, and n2 may be the same as described above, n2 may be 0,        1, or 2,    -   X₅₁ in Formulae CY2-1 to CY2-4 may be O, S,        N-[(L₇)_(b7)-(R₇)_(c7)], C(R₇)(R₈), Si(R₇)(R₈), Ge(R₇)(R₈), or        C(═O),    -   X₅₁ in Formulae CY2-5 to CY2-20 may be N, C(R₇), Si(R₇), or        Ge(R₇),    -   L₇, b7, R₇, and c7 may be the same as described above,    -   a22 may be an integer from 0 to 2,    -   a23 may be an integer from 0 to 3,    -   *indicates a binding site to CY₁ in Formula 1,    -   *′ indicates a binding site to M in Formula 1, and    -   *″ indicates a binding site to CY₃ in Formula 1.

In one or more embodiments, in Formula 1, a moiety represented by

may be a group represented by one of Formulae CY3-1 to CY3-12:

In Formulae CY3-1 to CY3-12,

-   -   X₃, R₃, Z₃, and n3 may be the same as described above, n3 is 0,        1, or 2, X₃₉ may be C(R_(39a))(R_(39b)),        N[(L₃₉)_(b39)-(R₃₉)_(c39)], O, S, or Si(R_(39a))(R_(39b)),    -   L₃₉ may be the same as explained in connection with L₃;    -   b39 and c39 may be the same as described in connection with b3        and c3,    -   R_(39a) and R_(39b) may be the same as described in connection        with R₃,    -   a32 may be an integer from 0 to 2,    -   a33 may be an integer from 0 to 3,    -   a34 may be an integer from 0 to 4,    -   a35 may be an integer from 0 to 5,    -   * indicates a binding site to CY₄ in Formula 1,    -   *′ indicates a binding site to M in Formula 1, and    -   *″ indicates a binding site to CY₂ in Formula 1.

In one or more embodiments, in Formula 1, a moiety represented by

may be a group represented by one of Formulae CY4-1 to CY4-26:

In Formulae CY4-1 to CY4-26,

-   -   X₄, R₄, Z₄, and n4 may be the same as described above, n4 may be        0, 1, or 2,    -   X₄₉ may be C(R_(49a))(R_(49b)), N[(L₄₉)_(b49)-(R₄₉)_(c49)], O,        S, or Si(R_(49a))(R_(49b)),    -   L₄₉ may be the same as explained in connection with L₄;    -   b49 and c49 may be the same as described in connection with b4        and c4,    -   R₄₁ to R₄₉, R_(49a), and R_(49b) may be the same as described in        connection with R₄,    -   a42 may be an integer from 0 to 2,    -   a43 may be an integer from 0 to 3,    -   a44 may be an integer from 0 to 4,    -   a45 may be an integer from 0 to 5,    -   a46 may be an integer from 0 to 6,    -   * indicates a binding site to CY₃ in Formula 1, and    -   *′ indicates a binding site to M in Formula 1.

In one or more embodiments, regarding Formula 1,

-   -   a moiety represented by

may be a group represented by Formulae CY1(1) to CY1(18) and CY1-CN(1)to CY1-CN(12), and(or)

-   -   a moiety represented by

may be a group represented by Formulae CY2(1) to CY2(20) and CY2-CN(1)to CY2-CN(15), and(or)

-   -   a moiety represented by

may be a group represented by Formulae CY3(1) to CY3(12) and CY3-CN(1)to CY3-CN(8), and(or)

-   -   a moiety represented by

may be a group represented by Formulae CY4(1) to CY4(10) and CY4-CN(1)to CY4-CN(12), but embodiments of the present disclosure are not limitedthereto:

In Formulae CY1(1) to CY1(18), CY1-CN(1) to CY1-CN(12), CY2(1) toCY2(20), CY2-CN(1) to CY2-CN(15), CY3(1) to CY3(12), CY3-CN(1) toCY3-CN(8), CY4(1) to CY4(10), and CY4-CN(1) to CY4-CN(12),

-   -   X₂ to X₄, Y₁, R₁ to R₄, and Z₁ to Z₄ may be the same as        described above,    -   R_(1a) to R_(1d) may be the same as described in connection with        R₁,    -   X₃₉ may be C(R_(39a))(R_(39b)), N[(L₃₉)_(b39)-(R₃₉)_(c39)], O,        S, or Si(R_(39a))(R_(39b)),    -   L₃₉ may be the same as explained in connection with L₃;    -   b39 and c39 may be the same as described in connection with b3        and c3,    -   R_(3a), R_(3b), R_(39a), and R_(39b) may be the same as        described in connection with R₃,    -   R_(4a) to R_(4d) may be the same as described in connection with        R₄,    -   R₁ to R₄, R_(1a) to R_(1d), R_(3a), R_(3b), and R_(4a) to R_(4d)        may each not be hydrogen,    -   *′ indicates a binding site to M in Formula 1,    -   *′ in Formulae CY1(1) to CY1(18) and CY1-CN(1) to CY1-CN(12)        indicates a binding site to CY₅ in Formula 1,    -   * in Formulae CY2(1) to CY2(20) and CY2-CN(1) to CY2-CN(15)        indicates a binding site to CY₁ in Formula 1,    -   *″ in Formulae CY2(1) to CY2(20) and CY2-CN(1) to CY2-CN(15)        indicates a binding site to CY₃ in Formula 1,    -   *″ in Formulae CY3(1) to CY3(12) and CY3-CN(1) to CY3-CN(8)        indicates a binding site to CY₂ in Formula 1,    -   * in Formulae CY3(1) to CY3(12) and CY3-CN(1) to CY3-CN(8)        indicates a binding site to CY₄ in Formula 1, and    -   * in Formulae CY4(1) to CY4(10) and CY4-CN(1) to CY4-CN(12)        indicates a binding site to CY₃ in Formula 1.

For example, the organometallic compound may be one of Compounds 1 to190, but embodiments of the present disclosure are not limited thereto:

Formula 1 has a 5-membered ring represented by CY₅, and a cyclometalatedring formed by CY₅, CY₂, CY₃, and M in Formula 1 is a 6-membered ring.Due to this structure, a binding angle between tetradentate ligand andmetal in Formula 1 is stable, and accordingly, the molecular stabilityof the organometallic compound represented by Formula 1 may be improved.

Also, in Formula 1, i) when X₅₁ is O, S, C(═O), or N, the sum of n1, n2,n3, and 4 is 1 or more, ii) when X₅₁ is N[(L₇)_(b7)-(R₇)C₇], C(R₇),Si(R₇), or Ge(R₇), R₇ is a cyano group-containing group or the sum ofn1, n2, n3, and 4 is 1 or more, and iii) when X₅₁ is C(R₇)(R₈),Si(R₇)(R₈), or Ge(R₇)(R₈), at least one selected from R₇ and R₈ is acyano group-containing group or the sum of n1, n2, n3, and n4 is 1 ormore. That is, the organometallic compound represented by Formula 1essentially includes at least one cyano group-containing group asdefined herein. Accordingly, charge-transfer characteristics of theorganometallic compound are improved, and thus, an electronic device,for example, an organic light-emitting device, in which theorganometallic compound is used, may have an improved luminescentefficiency and an easily controllable-emission wavelength band.

For example, the highest occupied molecular orbital (HOMO), lowestunoccupied molecular orbital (LUMO), singlet (Si), and triplet (Ti)energy levels of Compounds 61, 123, 124, 128, and 158 were calculated byusing a DFT method of the Gaussian program [structurally optimized atthe level of B3LYP, 6-31G(d,p)]. The evaluation results are shown inTable 1 below.

TABLE 1 HOMO LUMO T₁ energy level Compound No. (eV) (eV) (eV) 61 −5.014−2.453 1.961 123 −4.920 −2.419 1.906 124 −4.866 −2.396 1.878 128 −4.866−2.318 1.977 158 −4.617 −2.438 1.639

From the data in Table 1, it is confirmed that the organometalliccompound represented by Formula 1 has such electric characteristics thatare suitable for use in an electric device, for example, for use as adopant for an organic light-emitting device.

Synthesis methods of the organometallic compound represented by Formula1 may be recognizable by one of ordinary skill in the art by referringto Synthesis Examples provided below.

The organometallic compound represented by Formula 1 is suitable for usein an organic layer of an organic light-emitting device, for example,for use as a dopant in an emission layer of the organic layer.

Thus, another aspect of the present disclosure provides an organiclight-emitting device that includes:

-   -   a first electrode;    -   a second electrode; and    -   an organic layer that is disposed between the first electrode        and the second electrode,    -   wherein the organic layer includes an emission layer and at        least one organometallic compound represented by Formula 1.

The organic light-emitting device may have, due to the inclusion of anorganic layer including the organometallic compound represented byFormula 1, a low driving voltage, high efficiency, high power, highquantum efficiency, a long lifespan, a low roll-off ratio, and excellentcolor purity.

The organometallic compound of Formula 1 may be used between a pair ofelectrodes of an organic light-emitting device. For example, theorganometallic compound represented by Formula 1 may be included in theemission layer. In this regard, the organometallic compound may act as adopant, and the emission layer may further include a host (that is, anamount of the organometallic compound represented by Formula 1 issmaller than an amount of the host).

The expression “(an organic layer) includes at least one oforganometallic compounds” used herein may include a case in which “(anorganic layer) includes identical organometallic compounds representedby Formula 1” and a case in which “(an organic layer) includes two ormore different organometallic compounds represented by Formula 1.”

For example, the organic layer may include, as the organometalliccompound, only Compound 1. In this regard, Compound 1 may be included inan emission layer of the organic light-emitting device. In one or moreembodiments, the organic layer may include, as the organometalliccompound, Compound 1 and Compound 2. In this regard, Compound 1 andCompound 2 may be included in an identical layer (for example, Compound1 and Compound 2 all may be included in an emission layer).

The first electrode may be an anode, which is a hole injectionelectrode, and the second electrode may be a cathode, which is anelectron injection electrode, or the first electrode may be a cathode,which is an electron injection electrode, and the second electrode maybe an anode, which is a hole injection electrode.

In an embodiment, in the organic light-emitting device, the firstelectrode is an anode, and the second electrode is a cathode, and theorganic layer further includes a hole transport region disposed betweenthe first electrode and the emission layer and an electron transportregion disposed between the emission layer and the second electrode,wherein the hole transport region includes a hole injection layer, ahole transport layer, an electron blocking layer, or any combinationthereof, and wherein the electron transport region includes a holeblocking layer, an electron transport layer, an electron injectionlayer, or any combination thereof.

The term “organic layer” as used herein refers to a single layer and/ora plurality of layers disposed between the first electrode and thesecond electrode of the organic light-emitting device. The “organiclayer” may include, in addition to an organic compound, anorganometallic complex including metal.

The FIGURE is a schematic view of an organic light-emitting device 10according to an embodiment. Hereinafter, the structure of an organiclight-emitting device according to an embodiment and a method ofmanufacturing an organic light-emitting device according to anembodiment will be described in connection with the FIGURE. The organiclight-emitting device 10 includes a first electrode 11, an organic layer15, and a second electrode 19, which are sequentially stacked.

A substrate may be additionally located under the first electrode 11 orabove the second electrode 19. For use as the substrate, any substratethat is used in general organic light-emitting devices may be used, andthe substrate may be a glass substrate or a transparent plasticsubstrate, each having excellent mechanical strength, thermal stability,transparency, surface smoothness, ease of handling, and waterresistance.

The first electrode 11 may be formed by depositing or sputtering amaterial for forming the first electrode 11 on the substrate. The firstelectrode 11 may be an anode.

The material for forming the first electrode 11 may be selected frommaterials with a high work function to facilitate hole injection. Thefirst electrode 11 may be a reflective electrode, a semi-transmissiveelectrode, or a transmissive electrode. The material for forming thefirst electrode may be, for example, indium tin oxide (ITO), indium zincoxide (IZO), tin oxide (SnO2), and zinc oxide (ZnO). In one or moreembodiments, magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li),calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag) maybe used as the material for forming the first electrode.

The first electrode 11 may have a single-layered structure or amulti-layered structure including two or more layers. For example, thefirst electrode 11 may have a three-layered structure of ITO/Ag/ITO, butthe structure of the first electrode 110 is not limited thereto.

The organic layer 15 is located on the first electrode 11.

The organic layer 15 may include a hole transport region, an emissionlayer, and an electron transport region.

The hole transport region may be disposed between the first electrode 11and the emission layer.

The hole transport region may include a hole injection layer, a holetransport layer, an electron blocking layer, a buffer layer, or anycombination thereof.

The hole transport region may include only either a hole injection layeror a hole transport layer. In one or more embodiments, the holetransport region may have a hole injection layer/hole transport layerstructure or a hole injection layer/hole transport layer/electronblocking layer structure, which are sequentially stacked in this statedorder from the first electrode 11.

A hole injection layer may be formed on the first electrode 11 by usingone or more suitable methods selected from vacuum deposition, spincoating, casting, or Langmuir-Blodgett (LB) deposition.

When a hole injection layer is formed by vacuum deposition, thedeposition conditions may vary depending on a material that is used toform the hole injection layer, and the structure and thermalcharacteristics of the hole injection layer. For example, the depositionconditions may include a deposition temperature of about 100 to about500° C., a vacuum pressure of about 10⁻⁸ to about 10⁻³ torr, and adeposition rate of about 0.01 to about 100 Å/sec. However, thedeposition conditions are not limited thereto.

When the hole injection layer is formed using spin coating, coatingconditions may vary according to the material used to form the holeinjection layer, and the structure and thermal properties of the holeinjection layer. For example, a coating speed may be from about 2,000revolutions per minute (rpm) to about 5,000 rpm, and a temperature atwhich a heat treatment is performed to remove a solvent after coatingmay be from about 80° C. to about 200° C. However, the coatingconditions are not limited thereto.

Conditions for forming a hole transport layer and an electron blockinglayer may be understood by referring to conditions for forming the holeinjection layer.

The hole transport region may include at least one selected fromm-MTDATA, TDATA, 2-TNATA, NPB, β-NPB, TPD, Spiro-TPD, Spiro-NPB,methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine(TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonicacid (PANI/CSA),polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound representedby Formula 201 below, and a compound represented by Formula 202 below:

Ar₁₀₁ and Ar₁₀₂ in Formula 201 may each independently be selected from:

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anacenaphthylene group, a fluorenylene group, a phenalenylene group, aphenanthrenylene group, an anthracenylene group, a fluoranthenylenegroup, a triphenylenylene group, a pyrenylene group, a chrysenylenylenegroup, a naphthacenylene group, a picenylene group, a perylenylenegroup, and a pentacenylene group; and

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anacenaphthylene group, a fluorenylene group, a phenalenylene group, aphenanthrenylene group, an anthracenylene group, a fluoranthenylenegroup, a triphenylenylene group, a pyrenylene group, a chrysenylenylenegroup, a naphthacenylene group, a picenylene group, a perylenylenegroup, or a pentacenylene group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid group or a salt thereof, asulfonic acid group or a salt thereof, a phosphoric acid group or a saltthereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group.

In Formula 201, xa and xb may each independently be an integer from 0 to5, or 0, 1, or 2. For example, xa is 1 and xb is 0, but xa and xb arenot limited thereto.

R₁₀₁ to R₁₀₈, R₁₁₁ to R₁₁₉, and R₁₂₁ to R₁₂₄ in Formulae 201 and 202 mayeach independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₁-C₁₀ alkyl group (for example, a methyl group, an ethyl group, apropyl group, a butyl group, a pentyl group, a hexyl group, and so on),and a C₁-C₁₀ alkoxy group (for example, a methoxy group, an ethoxygroup, a propoxy group, a butoxy group, a pentoxy group, and so on);

a C₁-C₁₀ alkyl group and a C₁-C₁₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, and a phosphoric acidgroup or a salt thereof;

a phenyl group, a naphthyl group, an anthracenyl group, a fluorenylgroup, and a pyrenyl group; and

a phenyl group, a naphthyl group, an anthracenyl group, a fluorenylgroup, and a pyrenyl group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₁-C₁₀ alkyl group, and a C₁-C₁₀ alkoxy group, but they are notlimited thereto.

but embodiments of the present disclosure are not limited thereto.

R₁₀₉ in Formula 201 may be selected from:

a phenyl group, a naphthyl group, an anthracenyl group, and a pyridinylgroup; and

a phenyl group, a naphthyl group, an anthracenyl group, and a pyridinylgroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an aminogroup, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, ananthracenyl group, and a pyridinyl group.

According to an embodiment, the compound represented by Formula 201 maybe represented by Formula 201A, but embodiments of the presentdisclosure are not limited thereto:

R₁₀₁, R₁₁₁, R₁₁₂, and R₁₀₉ in Formula 201A may be understood byreferring to the description provided herein.

For example, the compound represented by Formula 201, and the compoundrepresented by Formula 202 may include compounds HT1 to HT20 illustratedbelow, but are not limited thereto:

A thickness of the hole transport region may be in a range of about 100Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When thehole transport region includes at least one of a hole injection layerand a hole transport layer, the thickness of the hole injection layermay be in a range of about 100 Å to about 10,000 Å, and for example,about 100 Å to about 1,000 Å, and the thickness of the hole transportlayer may be in a range of about 50 Å to about 2,000 Å, and for example,about 100 Å to about 1,500 Å. While not wishing to be bound by theory,it is understood that when the thicknesses of the hole transport region,the hole injection layer, and the hole transport layer are within theseranges, satisfactory hole transporting characteristics may be obtainedwithout a substantial increase in driving voltage.

The hole transport region may further include, in addition to thesematerials, a charge-generation material for the improvement ofconductive properties. The charge-generation material may behomogeneously or non-homogeneously dispersed in the hole transportregion.

The charge-generation material may be, for example, a p-dopant. Thep-dopant may be one selected from a quinone derivative, a metal oxide,and a cyano group-containing compound, but embodiments of the presentdisclosure are not limited thereto. Non-limiting examples of thep-dopant are a quinone derivative, such as tetracyanoquinonedimethane(TCNQ) or 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane(F4-TCNQ); a metal oxide, such as a tungsten oxide or a molybdeniumoxide; and a cyano group-containing compound, such as Compound HT-D1below, but are not limited thereto.

The hole transport region may include a buffer layer.

Also, the buffer layer may compensate for an optical resonance distancedepending on a wavelength of light emitted from the emission layer, andthus, efficiency of a formed organic light-emitting device may beimproved.

Then, an emission layer (EML) may be formed on the hole transport regionby vacuum deposition, spin coating, casting, LB deposition, or the like.When the emission layer is formed by vacuum deposition or spin coating,the deposition or coating conditions may be similar to those applied informing the hole injection layer although the deposition or coatingconditions may vary according to a compound that is used to form theemission layer.

Meanwhile, when the hole transport region includes an electron blockinglayer, a material for the electron blocking layer may be selected frommaterials for the hole transport region described above and materialsfor a host to be explained later. However, the material for the electronblocking layer is not limited thereto. For example, when the holetransport region includes an electron blocking layer, a material for theelectron blocking layer may be mCP, which will be explained later.

The emission layer may include a host and a dopant, and the dopant mayinclude the organometallic compound represented by Formula 1.

The host may include at least one selected from TPBi, TBADN, ADN (alsoreferred to as “DNA”), CBP, CDBP, TCP, mCP, Compound H50, and CompoundH51:

In one or more embodiments, the host may further include a compoundrepresented by Formula 301 below.

Ar₁₁₁ and Ar₁₁₂ in Formula 301 may each independently be selected from:

a phenylene group, a naphthylene group, a phenanthrenylene group, and apyrenylene group; and

a phenylene group, a naphthylene group, a phenanthrenylene group, and apyrenylene group, each substituted with at least one selected from aphenyl group, a naphthyl group, and an anthracenyl group;

Ar₁₁₃ to Ar₁₁₆ in Formula 301 may each independently be selected from:

a C₁-C₁₀ alkyl group, a phenyl group, a naphthyl group, a phenanthrenylgroup, and a pyrenyl group; and

a phenyl group, a naphthyl group, a phenanthrenyl group, and a pyrenylgroup, each substituted with at least one selected from a phenyl group,a naphthyl group, and an anthracenyl group.

g, h, i, and j in Formula 301 may each independently be an integer from0 to 4, and may be, for example, 0, 1, or 2.

Ar₁₁₃ to Ar₁₁₆ in Formula 301 may each independently be selected from:

a C₁-C₁₀ alkyl group, substituted with at least one selected from aphenyl group, a naphthyl group, and an anthracenyl group;

a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl, aphenanthrenyl group, and a fluorenyl group;

a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group,a phenanthrenyl group, and a fluorenyl group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a naphthylgroup, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, anda fluorenyl group; and

but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the host may include a compound representedby Formula 302 below:

Ar₁₂₂ to Ar₁₂5 in Formula 302 are the same as described in detail inconnection with Ar₁₁₃ in Formula 301.

Ar₁₂₆ and Ar₁₂₇ in Formula 302 may each independently be a C₁-C₁₀ alkylgroup (for example, a methyl group, an ethyl group, or a propyl group).

k and I in Formula 302 may each independently be an integer from 0 to 4.For example, k and I may be 0, 1, or 2.

When the organic light-emitting device is a full-color organiclight-emitting device, the emission layer may be patterned into a redemission layer, a green emission layer, and a blue emission layer. Inone or more embodiments, due to a stacked structure including a redemission layer, a green emission layer, and/or a blue emission layer,the emission layer may emit white light.

When the emission layer includes a host and a dopant, an amount of thedopant may be in a range of about 0.01 parts by weight to about 15 partsby weight based on 100 parts by weight of the host, but embodiments ofthe present disclosure are not limited thereto.

A thickness of the emission layer may be in a range of about 100 Å toabout 1,000 Å, for example, about 200 Å to about 600 Å. While notwishing to be bound by theory, it is understood that when the thicknessof the emission layer is within this range, excellent light-emissioncharacteristics may be obtained without a substantial increase indriving voltage.

Then, an electron transport region may be located on the emission layer.

The electron transport region may include a hole blocking layer, anelectron transport layer, an electron injection layer, or anycombination thereof.

For example, the electron transport region may have a hole blockinglayer/electron transport layer/electron injection layer structure or anelectron transport layer/electron injection layer structure, but thestructure of the electron transport region is not limited thereto. Theelectron transport layer may have a single-layered structure or amulti-layered structure including two or more different materials.

Conditions for forming the hole blocking layer, the electron transportlayer, and the electron injection layer which constitute the electrontransport region may be understood by referring to the conditions forforming the hole injection layer.

When the electron transport region includes a hole blocking layer, thehole blocking layer may include, for example, at least one of BCP,Bphen, and BAlq but embodiments of the present disclosure are notlimited thereto.

A thickness of the hole blocking layer may be in a range of about 20 Åto about 1,000 Å, for example, about 30 Å to about 300 Å. While notwishing to be bound by theory, it is understood that when the thicknessof the hole blocking layer is within these ranges, the hole blockinglayer may have improved hole blocking ability without a substantialincrease in driving voltage.

The electron transport layer may further include at least one selectedfrom BCP, Bphen, Alq3, BAIq, TAZ, and NTAZ.

In one or more embodiments, the electron transport layer may include atleast one of ET1 and ET25, but are not limited thereto:

A thickness of the electron transport layer may be in a range of about100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. Whilenot wishing to be bound by theory, it is understood that when thethickness of the electron transport layer is within the range describedabove, the electron transport layer may have satisfactory electrontransport characteristics without a substantial increase in drivingvoltage.

Also, the electron transport layer may further include, in addition tothe materials described above, a metal-containing material.

The metal-containing material may include a Li complex. The Li complexmay include, for example, Compound ET-D1 (lithium quinolate, LiQ) orET-D2.

The electron transport region may include an electron injection layer(EIL) that promotes flow of electrons from the second electrode 19thereinto.

The electron injection layer may include at least one selected from LiF,NaCl, CsF, Li₂O, and BaO.

A thickness of the electron injection layer may be in a range of about 1Å to about 100 Å, for example, about 3 Å to about 90 Å. While notwishing to be bound by theory, it is understood that when the thicknessof the electron injection layer is within the range described above, theelectron injection layer may have satisfactory electron injectioncharacteristics without a substantial increase in driving voltage.

The second electrode 19 is located on the organic layer 15. The secondelectrode 19 may be a cathode. A material for forming the secondelectrode 19 may be selected from metal, an alloy, an electricallyconductive compound, and a combination thereof, which have a relativelylow work function. For example, lithium (Li), magnesium (Mg), aluminum(Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In),or magnesium-silver (Mg—Ag) may be used as a material for forming thesecond electrode 19. In one or more embodiments, to manufacture atop-emission type light-emitting device, a transmissive electrode formedusing ITO or IZO may be used as the second electrode 19.

Hereinbefore, the organic light-emitting device has been described withreference to the FIGURE, but embodiments of the present disclosure arenot limited thereto.

Another aspect of the present disclosure provides a diagnosticcomposition including at least one organometallic compound representedby Formula 1.

The organometallic compound represented by Formula 1 provides highluminescent efficiency. Accordingly, a diagnostic composition includingthe organometallic compound may have high diagnostic efficiency.

The diagnostic composition may be used in various applications includinga diagnosis kit, a diagnosis reagent, a biosensor, and a biomarker.

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear orbranched saturated aliphatic hydrocarbon monovalent group having 1 to 60carbon atoms, and non-limiting examples thereof include a methyl group,an ethyl group, a propyl group, an iso-butyl group, a sec-butyl group, atert-butyl group, a pentyl group, an iso-amyl group, and a hexyl group.The term “C₁-C₆₀ alkylene group” as used herein refers to a divalentgroup having the same structure as the C₁-C₆₀ alkyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalentgroup represented by -OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group),and non-limiting examples thereof include a methoxy group, an ethoxygroup, and an iso-propyloxy group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a hydrocarbongroup formed by including at least one carbon-carbon double bond in themiddle or at the terminus of the C₂-C₆₀ alkyl group, and examplesthereof include an ethenyl group, a propenyl group, and a butenyl group.The term “C₂-C₆₀ alkenylene group” as used herein refers to a divalentgroup having the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbongroup formed by including at least one carbon-carbon triple bond in themiddle or at the terminus of the C₂-C₆₀ alkyl group, and examplesthereof include an ethynyl group, and a propynyl group. The term “C₂-C₆₀alkynylene group” as used herein refers to a divalent group having thesame structure as the C₂-C₆₀ alkynyl group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalentsaturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, andnon-limiting examples thereof include a cyclopropyl group, a cyclobutylgroup, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.The term “C₃-C₁₀ cycloalkylene group” as used herein refers to adivalent group having the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to amonovalent saturated monocyclic group having at least one heteroatomselected from N, O, P, Si and S as a ring-forming atom and 1 to 10carbon atoms, and non-limiting examples thereof include atetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term“C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalentgroup having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to amonovalent monocyclic group that has 3 to 10 carbon atoms, that has atleast one carbon-carbon double bond in the ring thereof, and that is notaromatic. Non-limiting examples thereof include a cyclopentenyl group, acyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀cycloalkenylene group” as used herein refers to a divalent group havingthe same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to amonovalent monocyclic group that has at least one heteroatom selectedfrom N, O, P, Si, and S as a ring-forming atom, 1 to 10 carbon atoms,and that has at least one carbon-carbon double bond in its ring.Examples of the C₁-C₁₀ heterocycloalkenyl group are a 2,3-dihydrofuranylgroup, and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀heterocycloalkenylene group” as used herein refers to a divalent grouphaving the same structure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent grouphaving a carbocyclic aromatic system having 6 to 60 carbon atoms, andthe term “C₆-C₆₀ arylene group” as used herein refers to a divalentgroup having a carbocyclic aromatic system having 6 to 60 carbon atoms.Non-limiting examples of the C₆-C₆₀ aryl group include a phenyl group, anaphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenylgroup, and a chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀arylene group each include two or more rings, the rings may be fused toeach other.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalentgroup having a carbocyclic aromatic system that has at least oneheteroatom selected from N, O, P, Si, and S as a ring-forming atom, and1 to 60 carbon atoms. The term “C₁-C₆ heteroarylene group” as usedherein refers to a divalent group having a carbocyclic aromatic systemthat has at least one heteroatom selected from N, O, P, and S as aring-forming atom, and 1 to 60 carbon atoms. Non-limiting examples ofthe C₁-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinylgroup, a pyrazinyl group, a pyridazinyl group, a triazinyl group, aquinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀ heteroarylgroup and the C₁-C₆₀ heteroarylene group each include two or more rings,the rings may be fused to each other.

The term “C₆-C₆₀ aryloxy group” used herein indicates -OA₁₀₂ (whereinA₁₀₂ is the C₆-C₆₀ aryl group), and a C₆-C₆₀ arylthio group used hereinindicates -SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as usedherein refers to a monovalent group (for example, having 8 to 60 carbonatoms) having two or more rings condensed to each other, having onlycarbon atoms as ring-forming atoms, and that is not aromatic in itsentire molecular structure. Examples of the monovalent non-aromaticcondensed polycyclic group include a fluorenyl group. The term “divalentnon-aromatic condensed polycyclic group” as used herein refers to adivalent group having the same structure as the monovalent non-aromaticcondensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” asused herein refers to a monovalent group (for example, having 2 to 60carbon atoms) having two or more rings condensed to each other, having aheteroatom selected from N, O, P, Si, and S, other than carbon atoms, asa ring-forming atom, and that is not aromatic in its entire molecularstructure. Non-limiting examples of the monovalent non-aromaticcondensed heteropolycyclic group include a carbazolyl group. The term“divalent non-aromatic condensed heteropolycyclic group” as used hereinrefers to a divalent group having the same structure as the monovalentnon-aromatic condensed heteropolycyclic group.

The term “C₅-C₃₀ carbocyclic group” as used herein refers to a saturatedor unsaturated cyclic group having, as a ring-forming atom, 5 to 30carbon atoms only. The C₅-C₃₀ carbocyclic group may be a monocyclicgroup or a polycyclic group.

The term “C₁-C₃₀ heterocyclic group” as used herein refers to asaturated or unsaturated cyclic group having, as a ring-forming atom, atleast one heteroatom selected from N, O, Si, P, and S other than 1 to 30carbon atoms. The C₁-C₃₀ heterocyclic group may be a monocyclic group ora polycyclic group.

At least one of substituents of the substituted C₅-C₃₀ carbocyclicgroup, substituted C₂-C₃₀ heterocyclic group, substituted C₁-C₆₀ alkylgroup, substituted C₂-C₆₀ alkenyl group, substituted C₂-C₆₀ alkynylgroup, substituted C₁-C₆₀ alkoxy group, substituted C₃-C₁₀ cycloalkylgroup, substituted C₁-C₁₀ heterocycloalkyl group, substituted C₃-C₁₀cycloalkenyl group, substituted C₁-C₁₀ heterocycloalkenyl group,substituted C₆-C₆₀ aryl group, substituted C₆-C₆₀ aryloxy group,substituted C₆-C₆₀ arylthio group, substituted C₁-C₆₀ heteroaryl group,substituted monovalent non-aromatic condensed polycyclic group, andsubstituted monovalent non-aromatic condensed heteropolycyclic group maybe selected from:

deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid group ora salt thereof, a sulfonic acid group or a salt thereof, a phosphoricacid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenylgroup, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,—CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group,an amidino group, a hydrazine group, a hydrazone group, a carboxylicacid group or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, aC₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅),—B(Q₁₆)(Q₁₇), and —P(═O)(Q₁₈)(Q₁₉);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,—CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group,a nitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, aC₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅),—B(Q₂₆)(Q₂₇), and —P(═O)(Q₂₈)(Q₂₉); and

—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉),

wherein Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may eachindependently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkyl groupsubstituted with at least one selected from deuterium, a C₁-C₆₀ alkylgroup, and a C₆-C₆₀ aryl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl groupsubstituted with at least one selected from deuterium, a C₁-C₆₀ alkylgroup, and a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromaticcondensed polycyclic group, and a monovalent non-aromatic condensedheteropolycyclic group.

When a group containing a specified number of carbon atoms issubstituted with any of the groups listed in the preceding paragraph,the number of carbon atoms in the resulting “substituted” group isdefined as the sum of the carbon atoms contained in the original(unsubstituted) group and the carbon atoms (if any) contained in thesubstituent. For example, when the term “substituted C1-C30 alkyl”refers to a C1-C30 alkyl group substituted with C6-C30 aryl group, thetotal number of carbon atoms in the resulting aryl substituted alkylgroup is C7-C60.

Hereinafter, a compound and an organic light-emitting device accordingto embodiments are described in detail with reference to SynthesisExample and Examples. However, the organic light-emitting device is notlimited thereto. The wording “B was used instead of A” used indescribing Synthesis Examples refers to that an identical molarequivalent of B was used in place of A.

EXAMPLE Synthesis Example 1: Synthesis of Compound 123 Synthesis ofIntermediate P2

120 milliliters (mL) of tetrahydrofuran (THF) and 40 mL of distilledwater were mixed with Compound P3-1 (5.3 grams (g), 20.5 millimoles,mmol), Compound P3-2 (7 g, 19.5 mmol), Pd(PPh₃)₄(1.6 g, 1.4 mmol), andK₂CO₃ (8.1 g, 58.6 mmol), and the mixture was stirred under reflux for12 hours. Once the reaction was completed, the temperature was loweredto room temperature, and the organic layer was extracted therefrom withmethylene chloride (MC). The combined organic extracts were dried overanhydrous magnesium sulfate (MgSO₄) and filtered. The obtained filtratewas concentrated under reduced pressure, and the residue was purified bycolumn chromatography using MC and hexane, thereby completing thepreparation of 5.8 g (73%) of Intermediate P2.

Synthesis of Intermediate P1

Intermediate P2 (5.8 g, 14.18 mmol),4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi(1,3,2-dioxaborolane) (7.2 g,28.36 mmol), PdCl₂(dppf) (0.83 g, 1.1 mmol), and potassium acetate (4.2g, 42.5 mmol) were mixed with 300 mL of toluene, and the mixture wasstirred under reflux for 18 hours. The temperature was lowered down toroom temperature.

The organic layer was extracted therefrom with MC, and the combinedorganic extracts were dried over anhydrous magnesium sulfate (MgSO₄) andfiltered. The obtained filtrate was subjected to reduced pressure andthe residue was purified by column chromatography using EA and hexane,thereby completing the preparation of 5.4 g (83%) of Intermediate P1.

Synthesis of Ligand 123L

Compound A (1.4 g, 2.9 mmol), Intermediate P1 (1.3 g, 2.9 mmol),Pd(PPh₃)₄ (0.24 g, 0.2 mmol), and K₂CO₃ (1.2 g, 8.7 mmol) were mixedwith 60 mL of THE and 20 mL of distilled water, and the mixture wasstirred under reflux for 12 hours. After the temperature was lowereddown to room temperature, the organic layer was extracted therefrom withMC. The combined organic extracts were dried over anhydrous magnesiumsulfate (MgSO₄) and filtered. The obtained filtrate was concentratedunder reduced pressure and the residue was purified by columnchromatography using MC and hexane, thereby completing the preparationof 1.2 g (56%) of Ligand 123L.

Synthesis of Compound 123

Ligand 123L (1.2 g, 1.6 mmol) and K₂PtCl₄ (0.7 g, 1.8 mmol) were mixedwith 50 mL of acetic acid, and the mixture was stirred under reflux for18 hours to complete the reaction. Then, the temperature was lowered.The obtained solid was filtered, and the residue was purified by columnchromatography using MC and hexane, thereby obtaining 0.56 g (37%) ofCompound 123. The obtained product was confirmed by Mass and HPLCanalysis.

HRMS (MALDI) calcd for C₅₁H₄₂N₄OPt: m/z 921.3006, Found: 921.3001

Synthesis Example 2: Compound 128 Synthesis of Ligand 128L

Compound A (2.1 g, 4.3 mmol), Compound B (2.0 g, 4.3 mmol),Pd(PPh₃)₄(0.35 g, 0.3 mmol), and K₂CO₃ (1.8 g, 13.0 mmol) were mixedwith 60 mL of THE and 20 mL of distilled water, and the mixture wasstirred under reflux for 12 hours. After the temperature was lowered toroom temperature, the organic layer was extracted therefrom with MC. Thecombined organic extracts were dried over anhydrous magnesium sulfate(MgSO₄) and filtered. The obtained filtrate was subjected to reducedpressure and the residue was purified by column chromatography using MCand hexane, thereby completing the preparation of 1.5 g (48%) of Ligand128L.

Synthesis of Compound 128

Ligand 128L (1.5 g, 2.1 mmol) and K₂PtCl₄ (1.1 g, 2.3 mmol) were mixedwith 60 mL of acetic acid, and the mixture was stirred under reflux for18 hours to complete a reaction. Then, the temperature was lowered. Theobtained solid was filtered, and the residue was purified by columnchromatography using MC and hexane, thereby obtaining 1.0 g (53%) ofCompound 128. The obtained product was confirmed by Mass and HPLCanalysis.

HRMS (MALDI) calcd for C₅₁H₄₂N₄OPt: m/z 921.3006, Found: 921.2997

Example 1

A glass substrate with an ITO electrode thereon was cut to a size of 50mm×50 mm×0.5 mm (mm=millimeter), sonicated in acetone, iso-propylalcohol and pure water, each for 15 minutes, and washed by exposure toUV ozone for 30 minutes, thereby preparing an ITO electrode on the glasssubstrate.

Then, m-MTDATA was deposited on the ITO electrode on the glass substrateat a deposition rate of 1 Angstrom per second (Å/sec) to form a holeinjection layer having a thickness of 600 Angstroms (Å), and α-NPD (NPB)was deposited on the hole injection layer at a deposition rate of 1Å/sec to form a hole transport layer having a thickness of 250 Å.

Compound 123 (dopant) and CBP (host) were co-deposited on the holetransport layer at deposition rates of 0.1 Å/sec and 1 Å/sec,respectively, to form an emission layer having a thickness of 400 Å.

BAIq was deposited on the emission layer at a deposition rate of 1 Å/secto form a hole blocking layer having a thickness of 50 Å, Alq₃ wasdeposited on the hole blocking layer to form an electron transport layerhaving a thickness of 300 Å, LiF was deposited on the electron transportlayer to form an electron injection layer having a thickness of 10 Å,and Al was vacuum-deposited on the electron injection layer to form asecond electrode (cathode) having a thickness of 1,200 Å, therebycompleting the manufacture of an organic light-emitting device havingthe structure of ITO/m-MTDATA (600 Å)/α-NPD (250 Å)/CBP+Compound 123(10%) (400 Å)/Balq(50 Å)/Alq₃(300 Å)/LiF(10 Å)/Al(1,200 Å).

Example 2 and Comparative Example 1

Organic light-emitting devices were manufactured in the same manner asin Example 1, except that in forming an emission layer, for use as adopant, corresponding compounds shown in Table 2 were used instead ofCompound 123.

Evaluation Example 1: Evaluation on Characteristics of OrganicLight-Emitting Devices

The driving voltage, the luminescent quantum efficiency, the roll-offratio, and the lifespan (T₉₅) of each of the organic light-emittingdevices manufactured according to Examples 1 and 2 and ComparativeExample 1 were evaluated and the results are shown in Table 2. Asevaluation devices, a current-voltage meter (Keithley 2400) and aluminance meter (Minolta Cs-1000A) were used, and the lifetime (T₉₅) (at6000 nit) was a relative value of the time taken when the luminancebecomes 95% of the initial luminance 100% with respect to the lifespan(T₉₅) of Example 1. The roll-off ratio was calculated by the followingequation:

Roll off={1−(efficiency(at9000nit)/maximum luminescentefficiency)}×100%  Equation 20

TABLE 2 Driving Luminescent Lifespan voltage quantum Roll-off (relativeVoltage Efficiency ratio value) Dopant (V) (%) (%) (T₉₅) Example 1Compound 4.26 22.6 10% 100% 123 Example 2 Compound 4.21 25.2 13% 112%128 Comparative Compound A 4.57 18.7 11%  17% Example 1

123

128

A

From Table 2, it can be seen that the organic light-emitting devices ofExamples 1 and 2 have better characteristics than the organiclight-emitting device of Comparative Example 1 in terms of drivingvoltage, luminescent quantum efficiency, roll-off ratio, and lifespan.

The organometallic compound according to embodiments has excellentelectric characteristics and thermal stability. Accordingly, an organiclight-emitting device including the organometallic compound may haveexcellent characteristics in terms of driving voltage, efficiency,power, color purity, and lifespan. The organometallic compound hasexcellent phosphorescent luminescent characteristics. Accordingly, theorganometallic compound can provide a diagnostic composition having highdiagnostic efficiency.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. An organometallic compound represented by Formula1:

wherein, in Formula 1, M is beryllium (Be), magnesium (Mg), aluminum(Al), calcium (Ca), titanium (Ti), manganese (Mn), cobalt (Co), copper(Cu), zinc (Zn), gallium (Ga), germanium (Ge), zirconium (Zr), rhutenium(Ru), rhodium (Rh), palladium (Pd), silver (Ag), rhenium (Re), platinum(Pt), or gold (Au), X₁ is a chemical bond, O, S, N(R′), P(R′), B(R′),C(R′)(R″), Si(R′)(R″), or N(R′)(R″), and when X₁ is a chemical bond, Y₁is directly bonded with M, a bond between X₁ and M is a covalent bond,X₂ and X₄ are each independently N and X₃ is C, a bond between X₂ and Mand a bond between X₄ and M are coordinate bonds and a bond between X₃and M is a covalent bond, Y₁ and Y₃ to Y₅ are each independently C or N,regarding a pair of X₂ and Y₃, a pair of X₂ and Y₄, a pair of Y₄ and Y₅,a pair of X₅₁ and Y₃, and a pair of X₅₁ and Y₅, components constitutingeach pair are connected to each other via a chemical bond, CY₁ to CY₅are each independently selected from a C₅-C₃₀ carbocyclic group and aC₁-C₃₀ heterocyclic group, provided that CY₄ is not a benzimidazolegroup, a benzoxazole group, or a benzothiazole group, a cyclometalatedring formed by CY₅, CY₂, CY₃, and M is a 6-membered ring, X₅₁ isselected from O, S, N-[(L₇)_(b7)-(R₇)_(c7)], C(R₇)(R₈), Si(R₇)(R₈),Ge(R₇)(R₈), C(═O), N, C(R₇), Si(R₇), and Ge(R₇), R₇ and R₈ areoptionally bonded to each other via a first linking group to form asubstituted or unsubstituted C₅-C₃₀ carbocyclic group or a substitutedor unsubstituted C₁-C₃₀ heterocyclic group, L₁ to L₄ and L₇ are eachindependently selected from a single bond, a substituted orunsubstituted C₅-C₃₀ carbocyclic group, and a substituted orunsubstituted C₁-C₃₀ heterocyclic group, b1 to b4 and b7 are eachindependently an integer from 1 to 5, R₁ to R₄, R₇, R₈, R′, and R″ areeach independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I,—SF₅, a hydroxyl group, a cyano group, a nitro group, an amidino group,a hydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkylgroup, a substituted or unsubstituted C₂-C₆₀ alkenyl group, asubstituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₁)(Q₂),—Si(Q₃)(Q₄)(Q₅),—B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉), c1 to c4 and c7 are eachindependently an integer from 1 to 5, Z₁ to Z₄ are each independently acyano group (CN)—containing group, a1 to a4 and n1, n2, n3, and n4 areeach independently an integer from 0 to 20, two of a plurality ofneighboring groups R₁ are optionally linked to form a substituted orunsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstitutedC₁-C₃₀ heterocyclic group, two of a plurality of neighboring groups R₂are optionally linked to form a substituted or unsubstituted C₅-C₃₀carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclicgroup, two of a plurality of neighboring groups R₃ are optionally linkedto form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃₀ heterocyclic group, two of aplurality of neighboring groups R₄ are optionally linked to form asubstituted or unsubstituted C₅-C₃₀ carbocyclic group or a substitutedor unsubstituted C₁-C₃₀ heterocyclic group, two or more neighboringsubstituents selected from groups R₁ to R₄, R₇, and R₈ are optionallylinked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic groupor a substituted or unsubstituted C₁-C₃₀ heterocyclic group, i) when X₅₁is O, S, C(═O), or N, the sum of n1, n2, n3, and n4 is 1 or more, ii)when X₅₁ is N[(L₇)_(b7)-(R₇)_(c7)], C(R₇), Si(R₇), or Ge(R₇), R₇ is acyano group-containing group or the sum of n1, n2, n3, and n4 is 1 ormore, iii) when X₅₁ is C(R₇)(R₈), Si(R₇)(R₈), or Ge(R₇)(R₈), at leastone selected from R₇ and R₈ is a cyano group-containing group or the sumof n1, n2, n3, and n4 is 1 or more, at least one of substituents of thesubstituted C₅-C₃₀ carbocyclic group, substituted C₁-C₃₀ heterocyclicgroup, substituted C₁-C₆₀ alkyl group, substituted C₂-C₆₀ alkenyl group,substituted C₂-C₆₀ alkynyl group, substituted C₁-C₆₀ alkoxy group,substituted C₃-C₁₀ cycloalkyl group, substituted C₁-C₁₀ heterocycloalkylgroup, substituted C₃-C₁₀ cycloalkenyl group, substituted C₁-C₁₀heterocycloalkenyl group, substituted C₆-C₆₀ aryl group, substitutedC₆-C₆₀ aryloxy group, substituted C₆-C₆₀ arylthio group, substitutedC₁-C₆₀ heteroaryl group, substituted monovalent non-aromatic condensedpolycyclic group, and substituted monovalent non-aromatic condensedheteropolycyclic group is selected from: deuterium, —F, —Cl, —Br, —I,—CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkylgroup, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at leastone selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃,—CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid group ora salt thereof, a sulfonic acid group or a salt thereof, a phosphoricacid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅),—B(Q₁₆)(Q₁₇), and —P(═O)(Q₁₈)(Q₁₉); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group; a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I,—CD₃,—CD₂H, —CDH₂, —CF₃,—CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid group ora salt thereof, a sulfonic acid group or a salt thereof, a phosphoricacid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenylgroup, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂),—Si(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), and —P(═O)(Q₂₈)(Q₂₉); and N(Q₃₁)(Q₃₂),—Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉), wherein Q₁ toQ₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ are each independentlyselected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkyl group substituted with at least oneselected from deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group,a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryl group substituted with at least one selected fromdeuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group.
 2. The organometalliccompound of claim 1, wherein CY₁ to CY₄ are each independently selectedfrom a benzene group, a naphthalene group, an anthracene group, aphenanthrene group, a triphenylene group, a pyrene group, a chrysenegroup, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, afuran group, a thiophene group, a silole group, an indene group, afluorene group, an indole group, a carbazole group, a benzofuran group,a dibenzofuran group, a benzothiophene group, a dibenzothiophene group,a benzosilole group, a dibenzosilole group, an azafluorene group, anazacarbazole group, an azadibenzofuran group, an azadibenzothiophenegroup, an azadibenzosilole group, a pyridine group, a pyrimidine group,a pyrazine group, a pyridazine group, a triazine group, a quinolinegroup, an isoquinoline group, a quinoxaline group, a quinazoline group,phenanthroline group, a pyrrole group, a pyrazole group, an imidazolegroup, a triazole group, an oxazole group, an iso-oxazole group, athiazole group, an isothiazole group, an oxadiazole group, a thiadiazolegroup, a benzopyrazole group, a benzimidazole group, a benzoxazolegroup, a benzothiazole group, a benzooxadiazole group, abenzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a5,6,7,8-tetrahydroquinoline.
 3. The organometallic compound of claim 1,wherein i) Y₃ to Y₅ are each C, a bond between X₅₁ and Y₃ and a bondbetween X₅₁ and Y₅ are each a single bond, and X₅₁ is O, S,N-[(L₇)_(b7)-(R₇)_(c7)], C(R₇)(R₈), Si(R₇)(R₈), Ge(R₇)(R₈), or C(═O),ii) Y₃ and Y₄ are each C, Y₅ is N, a bond between X₅₁ and Y₃ is a doublebond, a bond between X₅₁ and Y₅ is a single bond, and X₅₁ is N, C(R₇),Si(R₇), or Ge(R₇), iii) Y₃ and Y₅ are each C, Y₄ is N, a bond betweenX₅₁ and Y₃ is a single bond, a bond between X₅₁ and Y₅ is a double bond,and X₅₁ is N, C(R₇), Si(R₇), or Ge(R₇), iv) Y₃ is N, Y₄ and Y₅ are eachC, a bond between X₅₁ and Y₃ is a single bond, a bond between X₅₁ and Y₅is a double bond, and X₅₁ is N, C(R₇), Si(R₇), or Ge(R₇), or v) Y₃ to Y₅are each C, a bond between X₅₁ and Y₃ is a double bond, a bond betweenX₅₁ and Y₅ is a single bond, and X₅₁ is N, C(R₇), Si(R₇), or Ge(R₇). 4.The organometallic compound of claim 1, wherein R₁ to R₄, R₇, R₈, R′,and R″ are each independently selected from: hydrogen, deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an aminogroup, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, —SF₅, C₁-C₂₀ alkylgroup, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀alkoxy group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid group ora salt thereof, a sulfonic acid group or a salt thereof, a phosphoricacid group or a salt thereof, a C₁-C₁₀ alkyl group, a cyclopentyl group,a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, anadamantanyl group, a norbornanyl group, a norbornenyl group, acyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, aphenyl group, a naphthyl group, a pyridinyl group, and a pyrimidinylgroup; a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclooctyl group, an adamantanyl group, a norbornanyl group, anorbornenyl group, a cyclopentenyl group, a cyclohexenyl group, acycloheptenyl group, a phenyl group, a naphthyl group, a fluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, apyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a purinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, abenzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group,an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, anoxadiazolyl group, a triazinyl group, a dibenzofuranyl group, adibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, an imidazopyridinyl group, and animidazopyrimidinyl group; a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a cyclooctyl group, an adamantanyl group, anorbornanyl group, a norbornenyl group, a cyclopentenyl group, acyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthylgroup, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a pyrrolyl group, a thiophenyl group, a furanyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a pyridinyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolylgroup, an indolyl group, an indazolyl group, a purinyl group, aquinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group,a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an oxadiazolyl group, a triazinyl group, adibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group,a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinylgroup, and an imidazopyrimidinyl group, each substituted with at leastone selected from, and deuterium, —F, —Cl, —Br, —I,—CD₃,—CD₂H, —CDH₂,—CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, anamino group, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a cyclooctyl group, an adamantanyl group, anorbornanyl group, a norbornenyl group, a cyclopentenyl group, acyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthylgroup, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a pyrrolyl group, a thiophenyl group, a furanyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a pyridinyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolylgroup, an indolyl group, an indazolyl group, a purinyl group, aquinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group,a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an oxadiazolyl group, a triazinyl group, adibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group,a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinylgroup, an imidazopyrimidinyl group, and —Si(Q₃₃)(Q₃₄)(Q₃₅), andN(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇) and —P(═O)(Q₈)(Q₉), wherein Q₁ toQ₉ and Q₃₃ to Q₃₅ are each independently selected from: CH₃, —CD₃,—CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂,—CHDCH₃, —CHDCD₂H,—CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, and -CD₂CDH₂; an n-propyl group,an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butylgroup, a tert-butyl group, an n-pentyl group, an iso-pentyl group, asec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthylgroup; and an n-propyl group, an iso-propyl group, an n-butyl group, aniso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentylgroup, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, aphenyl group, and a naphthyl group, each substituted with at least oneselected from deuterium, a C₁-C₁₀ alkyl group, and a phenyl group. 5.The organometallic compound of claim 1, wherein R₁ to R₄, R₇, R₈, R′,and R″ are each independently selected from hydrogen, deuterium, —F, acyano group, a nitro group, —SF₅, —CH₃, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,—CFH₂, —C(CD₃)₃, groups represented by Formulae 9-1 to 9-19, groupsrepresented by Formulae 10-1 to 10-140, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅),—B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉):

wherein, in Formulae 9-1 to 9-19 and 10-1 to 10-140, * indicates abinding site to a neighboring atom, “Ph” indicates a phenyl group, and“TMS” indicates a trimethylsilyl group.
 6. The organometallic compoundof claim 1, wherein the cyano group-containing group is a cyano group ora first group substituted with at least one cyano group, wherein thefirst group is selected from a substituted or unsubstituted C₁-C₆₀ alkylgroup, a substituted or unsubstituted C₂-C₆₀ alkenyl group, asubstituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group.
 7. The organometalliccompound of claim 1, wherein the sum of n1, n2, n3, and n4 is 1, 2, 3,or
 4. 8. The organometallic compound of claim 1, wherein i) n1=n2=n3=0,and n4=1, ii) n1=n2=n4=0, and n3=1, iii) n1=n3=n4=0, and n2=1, iv)n2=n3=n4=0, and n1=1, v) n1=n2=0, and n3=n4=1, vi) n2=n3=0, and n1=n4=1,vii) n2=n4=0, and n1=n3=1, or viii) n1=n3=0, and n2=n4=1.
 9. Theorganometallic compound of claim 1, wherein i) X₁ is a chemical bond,and a moiety represented by

is a group represented by Formula CY1-B, or ii) X₁ is O, S, N(R′),P(R′), B(R′), C(R′)(R″), Si(R′)(R″), or N(R′)(R″), and a moietyrepresented by

is a group represented by Formula CY1-A:

wherein, in Formulae CY1-A and CY1-B, Y₁, CY₁, L₁, b1, R₁, c1, a1, Z₁,and n1 are the same as described in connection with claim 1, Y₂ and Y₆are each independently N or C, and a bond between Y₁ and Y₂, a bondbetween Y₁ and Y₆, and a bond between Y₆ and Y₂ are each a chemicalbond.
 10. The organometallic compound of claim 1, wherein a moietyrepresented by

in Formula 1 is a group represented by one of Formulae CY1-1 to CY1-40:

wherein, in Formulae CY1-1 to CY1-40, Y₁, R₁, Z₁, and n1 are the same asdescribed in connection with claim 1, n1 is 0, 1, or 2, X₁₉ isC(R_(19a))(R_(19b)), N[(L₁₉)_(b19)-(R₁₉)_(c19)], O, S, orSi(R_(19a))(R_(19b)), L₁₉ is the same as described in connection with L₁in claim 1, b19 and c19 are the same as described in connection with b1and c1 in claim 1, respectively, R₁₁ to R₁₉, R_(19a), and R_(19b) arethe same as described in connection with R₁ in claim 1, a12 is aninteger from 0 to 2, a13 is an integer from 0 to 3, a14 is an integerfrom 0 to 4, a15 is an integer from 0 to 5, a16 is an integer from 0 to6, a17 is an integer from 0 to 7, *′ indicates a binding site to M inFormula 1, and * indicates a binding site to CY₅ in Formula
 1. 11. Theorganometallic compound of claim 1, wherein a moiety represented by

in Formula 1 is a group represented by one of Formulae CY2-1 to CY2-20:

wherein, in Formulae CY2-1 to CY2-20, R₂, Z₂, and n2 are the same asdescribed in connection with claim 1, n2 is 0, 1, or 2, X₅₁ in FormulaeCY2-1 to CY2-4 is O, S, N-[(L₇)_(b7)-(R₇)_(c7)], C(R₇)(R₈), Si(R₇)(R₈),Ge(R₇)(R₈), or C(═O), X₅₁ in Formulae CY2-5 to CY2-20 is N, C(R₇),Si(R₇), or Ge(R₇), L₇, b7, R₇, and c7 are the same as described inconnection with claim 1, a22 is an integer from 0 to 2, a23 is aninteger from 0 to 3, * indicates a binding site to CY₁ in Formula 1, *′indicates a binding site to M in Formula 1, and indicates a binding siteto CY₃ in Formula
 1. 12. The organometallic compound of claim 1, whereina moiety represented by

in Formula 1 is a group represented by one of Formulae CY3-1 to CY3-12:

wherein, in Formulae CY3-1 to CY3-12, X₃, R₃, Z₃, and n3 are the same asdescribed in connection with claim 1, n3 is 0, 1 or 2, X₃₉ isC(R_(39a))(R_(39b)), N[(L₃₉)_(b39)-(R₃₉)_(c39)], O, S, orSi(R_(39a))(R_(39b)), L₃₉ is the same as described in connection with L₃in claim 1, b39 and c39 are the same as described in connection with b3and c3 recited in claim 1, respectively, R_(39a) and R_(39b) are thesame as described in connection with R₃ in claim 1, a32 is an integerfrom 0 to 2, a33 is an integer from 0 to 3, a34 is an integer from 0 to4, a35 is an integer from 0 to 5, * indicates a binding site to CY₄ inFormula 1, *′ indicates a binding site to M in Formula 1, and indicatesa binding site to CY₂ in Formula
 1. 13. The organometallic compound ofclaim 1, wherein a moiety represented by

in Formula 1 is a group represented by one of Formulae CY4-1 to CY4-26:

wherein, in Formulae CY4-1 to CY4-26, X₄, R₄, Z₄, and n4 are the same asdescribed in connection with claim 1, n4 is 0, 1, or 2, X₄₉ isC(R_(49a))(R_(49b)), N[(L₄₉)₄₉-(R₄₉)_(c49)], O, S, orSi(R_(49a))(R_(49b)), L₄₉ is the same as described in connection with L₄in claim 1, b49 and c49 are the same as described in connection with b4and c4 in claim 1, respectively, R₄₁ to R₄₉, R_(49a) and R_(49b) are thesame as described in connection with R₄ in claim 1, a42 is an integerfrom 0 to 2, a43 is an integer from 0 to 3, a44 is an integer from 0 to4, a45 is an integer from 0 to 5, a46 is an integer from 0 to 6, *indicates a binding site to CY₃ in Formula 1, and *′ indicates a bindingsite to M in Formula
 1. 14. The organometallic compound of claim 1,wherein the organometallic compound is one of Compounds 1 to 190 below:


15. An organic light-emitting device comprising: a first electrode; asecond electrode; and an organic layer disposed between the firstelectrode and the second electrode, wherein the organic layer comprisingan emission layer, and wherein the organic layer comprises at least oneorganometallic compound of claim
 1. 16. The organic light-emittingdevice of claim 15, wherein the first electrode is an anode, the secondelectrode is a cathode, and the organic layer further comprises a holetransport region disposed between the first electrode and the emissionlayer and an electron transport region disposed between the emissionlayer and the second electrode, wherein the hole transport regioncomprises a hole injection layer, a hole transport layer, an electronblocking layer, or any combination thereof, and wherein the electrontransport region comprises a hole blocking layer, an electron transportlayer, an electron injection layer, or any combination thereof.
 17. Theorganic light-emitting device of claim 15, wherein the emission layercomprises the at least one organometallic compound.
 18. The organiclight-emitting device of claim 17, wherein the emission layer furthercomprises a host, and wherein an amount of the host is greater than anamount of the at least one organometallic compound.
 19. A diagnosticcomposition comprising at least one organometallic compound of claim 1.